Episode 69: Social Science and Critical Rationalism

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Unofficial, reviewed transcript. It may still contain mistakes; check the podcast when wording matters.

Speakers are labeled by first name where identified. Unidentified-speaker labels may refer to different people. Bracketed question marks indicate uncertain wording.

Transcript

[00:00:10]  Bruce: Welcome to The Theory of Anything podcast. We've got Peter and Brian again. How's it going, Brian?

[00:00:16]  Brian: Oh, going really well. How are you guys?

[00:00:18]  Unidentified speaker: Good.

[00:00:19]  Peter: Just great. Nice to see you guys again.

[00:00:22]  Brian: Absolutely.

[00:00:23]  Bruce: So the last time we had Brian on the podcast, that was probably weeks ago for our listeners, but this is actually not that long since we're recording it, but we released episodes out of order. But last time we had Brian on the podcast, we talked with him about his interest in both David Deutsch's ideas, the Four Strands, and also how it could be applied with twin studies, which is something that a lot of fans of David Deutsch are very down on. That was a very interesting discussion. But we didn't have time to get into, how do you even apply Karl Popper's epistemology to fields like Brian's, or to social sciences in general, or to economics, right? How do you apply his epistemology to these fields? So this is something that I know that I've been giving some thought to, and I know Brian's been giving some thought to. And one of the things that had led to me thinking about it was Brian talking with me about it.

[00:01:27]  Bruce: He started to email me saying, how would you apply Karl Popper's epistemology to social sciences? And I hadn't given it much thought prior to that point. He started sending me some white papers to look at. And one of them was the one Bruce Caldwell's Clarifying Popper that we did a summary of at the beginning of this episode, at least that will be when we get done recording it. But there was other ones he sent me as well. And so we've had some discussion about this. And so I wanted to bring him back on the show and I wanted to talk about what I thought was a super interesting topic that I don't think I've seen that many people talk about. So Brian, maybe let me just start with you. How did you get interested in trying to apply Popper's epistemology to social sciences and economics and into your field? And was that something that was a little bit hard to figure out what to do?

[00:02:23]  Bruce: Or did you kind of have an idea where you were going from the beginning?

[00:02:26]  Brian: Yeah, no, that's a good question, and to answer that second question first, no, I didn't have, there's no roadmap or, you know, well plotted out course. So to give a little background, it's almost, I don't know if it's embarrassing, just regrettable. I only became familiar with Popper's work a few, a handful of years ago. We just, philosophy, sort of philosophy of science, philosophy of mind, which is another area I'm really interested in at this point in my career. They just were not parts of the curriculum in my program when I was working on my master's and PhD. And so we would get, you would get sort of a smattering of it, a lot of Bentham and Beccaria in terms of utilitarianism and the role that that played in certain criminological theories, deterrence theory in particular. So there was, I don't want to say there was no exposure to what we might think of as sort of more classic philosophy or moral philosophy, that kind of thing.

[00:03:29]  Unidentified speaker: There was a bit.

[00:03:31]  Unidentified speaker: And part of the fault is mine.

[00:03:32]  Brian: I didn't, I just wasn't as interested at that point in my life for whatever reason. And so the big thing that sort of snapped my attention towards Popper was Deutsch, reading Beginning of Infinity, which then prompted the need to read Fabric of Reality. And there were a variety of other influences, too, that are a little more indirect because they weren't necessarily dealing directly with Popper. But folks like Douglas Hofstadter, who I really admire, I mean, just a remarkable mind. And so it was a very indirect pathway. And I also I feel compelled to put in a disclaimer. I haven't sorted out all my thoughts on this yet. I'm this is very much a work in progress, and nor should I ever be confused with an expert on Popperian thought. I'm still but a student of that. But I have, you know, it's kind of like wanting to bolt the wings on the airplane in flight, because I think the ideas are useful.

[00:04:37]  Brian: And so that's why I'm sort of actively trying to work on them and also clarify them at the same time, if that makes any sense.

[00:04:44]  Bruce: Yes, it does. By the way, this is a total tangent. You mentioned Douglas Hofstadter. I just barely ordered Melanie Mitchell's book, Analogy Making as Perception, since [unclear] Douglas Hofstadter’s student.

[00:04:56]  Brian: You might want to also check out, do you have surfaces and essences?

[00:05:00]  Bruce: Yes, that's one of my favorite books. I hated it the first time I listened to it. I really thought it was terrible. And then I thought about it for a while and I started to realize he's got he's I don't know how close he is to the truth, but he's got some creative ideas here that are worth another look.

[00:05:17]  Brian: No doubt about it. Just very briefly, a bit more on this topic. It's funny, the the book I've relied more heavily on in terms of my work and drawing from Hofstadter was I Am a Strange Loop. And that was because I wrote a paper a few years back trying to sort out the intersections of behavioral genetics and consciousness—study of consciousness.

[00:05:41]  Unidentified speaker: Yeah, interesting.

[00:05:42]  Brian: And so I don't know if I've ever sent you that paper. I'm happy to send it to you if you like.

[00:05:46]  Bruce: Oh, yes, by all means.

[00:05:48]  Brian: Yeah, and kind of it was a very cool moment. I was able to share the paper with Hofstadter and he thought it was interesting and at least not crazy. So that made me feel good. But which is not to say he endorsed it. I’m just—this is—

[00:06:04]  Unidentified speaker: right.

[00:06:04]  Bruce: No, I understood.

[00:06:07]  Brian: I don't want to I never want to put words in another colleague's mouth. But yeah, it was just a cool moment for me as someone who admires his work.

[00:06:13]  Bruce: Yeah, and then Hofstadter said to me, this is exactly what I've been thinking.

[00:06:18]  Unidentified speaker: Yeah, that’s right.

[00:06:18]  Unidentified speaker: Yeah,

[00:06:19]  Brian: no, it’s not quite that. But it was it was still it was pretty cool.

[00:06:25]  Unidentified speaker: Yeah.

[00:06:26]  Brian: And so I have actually I'm sort of where you are. I have Mitchell's book as well. I've not yet had a chance to read it. But the topic of analogy is one we can spend a lot of time on maybe another day. But because I'm becoming increasingly interested in the arguments that he he and his co-author plot out in that book. And I'm interested in Mitchell's where she develops it as well. I don't know. I don't have strong feelings about the veracity of it yet, but I'm definitely intrigued.

[00:06:54]  Bruce: Yeah, it's it's a creative idea. Let's let's put it that way. It'd be nice if we could figure out how to do something that could be implemented and we could actually try it out. But we don't seem to be at that level of knowledge with it with the theory yet.

[00:07:08]  Brian: Yep, maybe not quite yet, but who knows, you know, plenty of opportunity for insight to come. So we'll see.

[00:07:17]  Bruce: Okay, so let's talk about some of the difficulties of trying to apply Popper to the softer sciences.

[00:07:27]  Brian: So, oh, it hurts me to hear you say that, but go ahead.

[00:07:32]  Bruce: Yeah, so I don't mean that in an offensive way.

[00:07:35]  Unidentified speaker: Let me clarify,

[00:07:36]  Unidentified speaker: let me clarify.

[00:07:38]  Bruce: I've always felt that the term softer sciences, unfortunately, is sometimes like a pejorative in some people's mouths.

[00:07:45]  Unidentified speaker: Yeah.

[00:07:45]  Bruce: But I feel like it's a meaningful statement, right? Like some sciences, we've developed them to the point where we've got these really very specific mathematical theories with really high empirical content. Obviously, I have physics in mind here, right?

[00:08:03]  Unidentified speaker: Sure,

[00:08:04]  Unidentified speaker: yeah.

[00:08:04]  Bruce: Then it's kind of a sliding scale. Chemistry is a hard science. It's got these really specific mathematical theories with high empirical content. And then you get down to biology, and it's somewhat... It relies very heavily on mathematical models, but it's nothing like physics, and there's a lot of talking around things. And then you get into social sciences, and it sort of depends. We call it social sciences, and that's a broad field. If you look at psychology, there are some aspects of psychology, and very big deals in the psychology department, that are very, very hard science.

[00:08:47]  Brian: Yes, neurobiology, neuroscience.

[00:08:49]  Bruce: Yeah, right. And then there's others that nobody claims are. We know that certain types of psychological theories, nobody's pretending that they're like physics. They're doing their best to figure out how to apply what they see as a scientific method. With this, they do try to follow what I would say is, as close as they can, a critical rationalist or falsificationist type of approach, where you're trying to test, okay, if I prompt this person, I've read things and this isn't my field, but let's say that we're testing whether if we put subliminal messages up, if that causes the person to think about whatever the subliminal message was, even though they couldn't consciously see it. So we actually do an experiment and we've got two hypotheses. And then we got a control group, and we put up the subliminal message for one group and we don't for the other.

[00:09:55]  Bruce: And then we see that the person actually mentions that word more often, or it causes them to be more likely to act in a certain way or something like that. Like there's been experiments to this effect. I don't know what the outcomes were. I don't know them off the top of my head here. But that is following a critical rationalist approach, right? You've got two theories. You're trying to do an experiment. It's going to falsify one of the two theories. You have a control set. You're doing a randomized controlled trial, so that you can make claims about causation. You know, there is this falsificationist approach that is being used in these fields in a lot of cases, right? Well, I was going to say, then you got like economics, which is like, I'm not even sure how to... Bruce Caldwell's paper was largely about trying to apply it to economics.

[00:10:48]  Bruce: That's a lot tougher. I mean, like, I had to stop and think about how would you apply Karl Popper's epistemology to economics? And that's even harder than social sciences, right? Because then you have so many causes that it's basically impossible to try to do a randomly controlled trial in economics and to therefore control what the other causes are. So how would you even go about applying Karl Popper's epistemology to economics? Anyhow, that would be kind of the sort of problems that I started to realize when I started talking with Brian about this. I had really not given this much thought prior to that point. And those are all really good questions. So, Brian, like in your field, you've given this some thought specific to your field, right? How would you go about trying to apply Karl Popper's epistemology to your field?

[00:11:48]  Brian: Well, I think at least I can tell you sort of where my thinking is now on it. And I can't obviously assume that it won't change moving forward. But the general approach I would want to take is one that may, maybe it might rightly be accused of cheating a little bit, because I don't know that I would want to import every single part of Popper's vision of things and then try and make that, you know, coherent with sort of how we study behaviors maybe or psychopathology or something like that. But so I guess I want more of a a la carte type approach. And so I'll describe it. And then, you know, we can talk about whether that seems fair enough or it's wrongheaded or something like that. But so one of the first, I'll tell you, this is more just a general point that both that I had never really thought clearly about until reading Popper and Deutsch and a few others.

[00:12:47]  Brian: And that's the just the issue of verificationism and the the problem of thinking about science as being in the verification business. I mean, for me, at least it was quite meaningful in terms of changing how I thought about that, because it was for me, it was a combination of either not thinking about the topic very much at all or thinking about it very much in the way that, you know, I think it would have been like Francis Bacon would have described how science works, sort of the inductionist type approach. And I mean, that really when you it's a simple idea that pervades a lot of different things. And what I think is important about it is that just a simple reality. And to me, this is not that revolutionary in the sense that if you pressed any one of my colleagues enough, they would tell you the same thing. One particular study is not sufficient to verify anything, at least not to the point where we would say, well, we're not going to test this part of social bond theory anymore because it is, I mean, it's true.

[00:14:02]  Brian: We're going to stop. We would not, you know, even someone who would, you know, we might disagree about falsificationism. I don't think it would be fair to them to say that they would want to stop with a study and not at least think it provisional evidence. And so I think that really does matter and really is important. And the broader reason it matters, and others talk about this too, and so we don't have to go into it right now or can go into it later. But the idea, I think there's probably some actual genuine problems that arise, just even in the lay public, when you think of science as verifying things, it sort of puts you in the direction of thinking scientists or science as being an authority. And I don't, you know, I think that actually is a problem if we fall too far down that rabbit hole. But we will leave that aside for now. So I certainly would want to lean away from the idea that we're verifying anything when we study things in behavioral and psychiatric sciences.

[00:15:14]  Brian: But what about falsification? Like you said, it's very tricky.

[00:15:19]  Unidentified speaker: And I don't know.

[00:15:23]  Brian: I don't guess I would push back really hard or at all with the argument that, well, you don't falsify things in the way physics falsifies things. I agree. But I guess my only aside would be I don't know that physics always falsifies things in the way that folks think they do. I mean, Newtonian mechanics giving way to...

[00:15:47]  Unidentified speaker: And this is not a criticism.

[00:15:51]  Brian: This is a pat on the back in terms of this is what you should do. When relativity or rather Newtonian mechanics gives way to relativity, that's how it's supposed to work, I would think. And then this is where I would... That's a good example to draw in Deutsch. Relativity was the better explanation for how things worked. Doesn't mean it's the explanation. It's the better one now. But as there's no secret in physics, it doesn't square well with quantum mechanics, so there's work to be done in some form. I think all of those things apply in the behavioral sciences, in the psychiatric sciences. This is where when we're talking about importing some of these ideas, I think Deutsch's idea of a good explanation and his operationalization of that is extremely valuable. Something that is, when you're purport to explain some phenomena, you want that explanation to have as much breadth and width as you can, you want to explain as much as you can, and you want it hard to vary.

[00:17:05]  Brian: And that just simple insight, it really does matter, because so you take the field of criminology, I mentioned Bentham and Beccaria, and there were many others as well, right? But in terms of our roots back into the Enlightenment, the rejection of the idea that people committed crimes because of demons that were possessing them and causing them to do these reprehensible things, and thus they were souls in need of salvation, when it was very much revolutionary for someone like Bentham to come along and argue, no, look, these are folks maximizing pleasure, minimizing pain. And the way that you order society in terms of punishments and consequences are going to inform how these rational actors maximize pleasure and minimize pain. I'm not saying Bentham was right, but I'm saying that's very much a cogent type of testable argument. And so in that way, it's a much better explanation than demons.

[00:18:14]  Brian: And I say that as somebody who loves possession movies, because I do.

[00:18:20]  Unidentified speaker: Can I throw something out real quick?

[00:18:22]  Peter: I just had a kind of a random aha moment here. I hope it doesn’t—I hope it keeps us on track. But I started thinking about, well, what makes a soft science soft from a more David Deutsch, Karl Popper kind of perspective? And I started thinking about David Deutsch's idea that human knowledge, the growth of knowledge is fundamentally unpredictable because it's tied into creativity and consciousness and things that we don't really understand. It goes along with Popper's ideas against historicism and that you can't use social science to predict the future. So it seems to me that perhaps the definition of social science is that you have this growth of knowledge aspect to it because you're talking about human beings and that's what we do. So it could be something that perhaps social scientists should be more aware of, maybe, thinking about just the fundamental unpredictability of knowledge growth.

[00:19:43]  Peter: Does that make sense?

[00:19:46]  Brian: I think so. I don't know that that's at odds, though, with, say, the idea that we can study neurological functioning to understand major depressive disorder or anything like that. So I don't know that anything you said I really would take deep issue with, because I don't know that it conflicts with the idea of what the so-called social sciences are really doing. I mean, I think it could depend on the topic, too, though. And if we sat here long enough, maybe it means more in a field like economics or political science, because I think that would sort of tie into Popper's myth of the framework. And you guys can correct me if I'm wrong, right? This idea of historical trends and to what extent do they matter and those types of things, assuming that, you know...

[00:20:42]  Peter: Yeah, I know for myself, when I really started reflecting on knowledge growth, it kind of makes a, you know, it has a really a far reach, we'll say that. Whenever you hear predictions all the time about, I don't know, climate change or what's going to happen. And, you know, I started thinking, you know, maybe climate change wasn't the best example. That's a loaded thing.

[00:21:11]  Bruce: It's actually a pretty good example. It's actually a pretty good example.

[00:21:14]  Peter: It's so tied in to everything. All predictions are so tied in to knowledge growth, down to the individual level. And it just, it really makes it makes it hard.

[00:21:26]  Brian: I think, no, I think I have a little better sense of your comment now. And so I think it's a good point. And maybe the implication of it is that we try to get out of the prediction business as much as we can. And this is another reason why in terms of like trying to predict what will happen in the future. And maybe, I don't know, again, academic freedom means folks get to spend their time doing what they enjoy and what they want. But for me, it has sharpened my focus, at least on explanations and the development of ever better ones. Because while they may not enable me to predict the future, the reach that good explanation has, as you know, sort of Deutsch described, is pretty remarkable. And so I think that concept in particular, too, is one that matters for me in terms of when we build theories or explanations for anything in the behavioral sciences, whether it's the developmental origins of schizophrenia or where crime comes from, a whole variety of things.

[00:22:35]  Brian: The search for better and better and better explanation is something that really holds my attention quite a bit.

[00:22:44]  Bruce: So let me try to steel man what I think Peter is getting at.

[00:22:48]  Brian: Yeah, yeah, please.

[00:22:50]  Bruce: So let's intentionally take the worst examples we can so that we can show the problem that I think we're kind of hinting at. So when I studied Psychology 101 in college, one of the most interesting classes I ever took and almost made me want to go into psychology as a field.

[00:23:12]  Unidentified speaker: Sure.

[00:23:14]  Bruce: But psychology, a lot of the studies that they do, I think that they cause, as Peter might say, it causes his bullcrap meter to go off. So one I just happened to remember is that they did something where they were introducing the people that were in the experiment to information about old age or showing them older people, or maybe it was even just subliminal in some cases. And then they would measure how long it took them to walk down the hallway to leave the facility, unbeknownst to the person who's in the experiment. And what they found was that when they primed people with thoughts about old age, that they walked much slower down the hallway and they tended to stoop more. And so this was a real study that they brought up in my class, right?

[00:24:18]  Unidentified speaker: Sure.

[00:24:18]  Bruce: Now, I actually don't find this to be like completely unbelievable. Like, I believe we are primed by thoughts like this. And it could well be that showing me pictures of old age would cause me to maybe act it a bit more or something like that. So I'm not even saying that it's wrong. But you can almost immediately see why people might feel very skeptical of this study because it's trying to find a law or something that is going to be so obviously mitigated by so many other things. And so you would come away, even if it was a good randomly controlled trial, even if, you know, I would really want to see it replicated a whole lot of times. Before I would give it much credence at all as a theory. And then when it really comes down to it, it's hard to believe you actually found some sort of law of human nature. Even if it was true at this time under this circumstance, it seems like it would just depend on culturally how we looked at older people.

[00:25:23]  Bruce: Maybe this is purely for a certain culture, right? And it may not even replicate into other cultures. And therefore, you're not actually finding something about human nature at all. You may have only found something that was really parochial to the way Western culture looks at old people because you were using students or whatever, and they were mostly from Western culture. And so I think that there's a natural skepticism. And I know that when I talk with fans of David Deutsch online, they'll quote things like this, and they'll have really big concerns not just with that study, but almost with the whole field, right? Because there is no such thing, you'll hear them sometimes say, there is no such thing as human nature, that we're universal explainers, so there is no human nature. You can't study human nature. Any attempt to study human nature is false because we're universal explainers and things can change.

[00:26:20]  Bruce: Even if you, and Deutsch used this example in his book, even if you tried to study genetically what, you know, the genetic influence of good looks, culturally that might change, right, in what we consider good looking. So that genetic factor that you found would turn out to be completely, might turn out to be completely parochial to just a certain culture that could tomorrow change into a different culture with a different standard for what is considered good looks or even just a different standard for what we consider attractive, maybe not even basing it on good looks. So I think this is the steel man criticism that I sense Peter is getting at, is that even just the attempt to use the scientific method, critical rationalism, let's say, on some of the things that these fields are trying to study, maybe they're just mistaken from the outset, and we shouldn't even be trying to do this.

[00:27:21]  Bruce: By the way, I don't agree with anything I just said.

[00:27:23]  Unidentified speaker: No, no, I understand.

[00:27:24]  Unidentified speaker: Yeah, yeah, yeah.

[00:27:26]  Bruce: In fact, I'd be happy to offer some really strong criticism on what I just said, but I would like to get your reaction to this point of view.

[00:27:34]  Brian: Yeah, so I guess kind of in the spirit of generosity, I would certainly concede that there are among those points that you made some fair ones and just a reasonable description of how things work. I think what I would say a few things. One is any particular study, say, take that, the one, the hypothetical you described, that in and of itself would not and should not constitute a test that, you know, were it to produce statistically significant results, tell you something fundamental about human nature. At best, I think it could tell you, maybe tell you something about a part of human nature. But one particular experiment in and of itself is, that's not really what it would be attempting to do even. The other thing that I think is tricky is, one, I would not push back against the idea that taste and cultures can change, do change. But, so I think there are a few interesting actual points to make on that.

[00:28:52]  Brian: Some of them have to do with aesthetics and relate directly to arguments Deutsch has made about there being, one, not a bright line between the arts and the humanities and the rest of the sciences, that all of them are sort of tapping into actual beauty, actual, you know, things that exist. They're all trying to get closer to truth, so to speak. And so I think in that regard, absolutely, culture can change. But if Deutsch is correct, then we would expect there to be some things that persist, if they actually are closer to this type of aesthetic truth or truth about beauty or whatever the case might be. Because we would expect those things to persist, at least to some extent. It doesn't mean that everything is unchanging in regards to culture and things that leisure activities or whatever the case might be. So I don't dispute that that can and does happen.

[00:29:55]  Brian: But I think one, well, another sort of related point is that the engines of that change are humans. And humans, our psychological and emotional lives reside in our neurological functioning and our central nervous system. And so you get not just top-down influence of culture, but you get bottom-up effects of individuals on that culture. And so culture is not this sort of supra-organism, to use Durkheim's term. It's not an uncaused cause. It comes from somewhere. And while I certainly can see that it has effects, it also, there are things that affect it, even historical trends, whatever. So anyway, then getting back to another point, I think one, we sort of maybe in your thought experiment allowed for us to just assume this to be true, but you know, otherwise, you know, assuming it's not true, one of the first places to start is, you know, the methodological, sort of the boring part, so to speak, of research.

[00:31:00]  Brian: And that's how big was the sample? Did it have adequate statistical power? Was there an error, just an honest error that crept in? Because that can happen. And you know, a whole variety of things that we would need to think about before we would assume very much at all about these types of issues. And honestly, some of this, I think, are avoidable sources of consternation. You know, if the larger, sort of, lay public consumers of scientific research didn't generally have a view of science as verifying things, more as, you know, provisionally looking at topics and either, you know, sort of falsifying or failing to falsify. And we'll come back to that in a minute. But if you look at, you know, this study had, you know, I look at the paper or it's covered in the Wall Street Journal, the New York Times or any other outlet. And, you know, they had a bunch of statistically significant results.

[00:31:58]  Brian: And I knew that because it's got a little asterisk by the coefficient there in the table. And I don't really, you know, it matters only to me that this seems important. And, oh, by the way, science verifies these hypotheses. So this particular hypothesis about human psychology seems verified. I mean, that can be, I think that it can be a place where we sort of can err in our thinking about what a particular study means.

[00:32:26]  Unidentified speaker: Right, right.

[00:32:28]  Bruce: So, OK, so let me take the example of people walking slower because they were exposed to stuff about old age. Like, I don't know, like, I would I find that still a fascinating study, even though I can understand why people's bullcrap meter goes off with it. The question, though, is what is it that I should be taking away from this study? And I don't think there's an obvious answer. Probably I should not be taking away that if I want people to walk more slowly, I should expose them to stuff about old age. I suspect that that won't work in a lot of cases. It wouldn't be useful anyhow. But I do come away with this idea that we are impacted about what we're currently thinking about, that it actually changes the way we think about things. And I think that's something that we've seen repeated in tests all over the place, where if you have a primed thought, that it does change the way you think about things.

[00:33:25]  Bruce: I think about here the case where they had the experiment where they gave people a candle and thumbtacks in a little box, and they're supposed to figure out how to light the candle and stick it to the wall. And whether you can complete the task or not comes down to whether you think of the box as the box containing the items you're allowed to use or if the box is one of the items that you're allowed to use. And if the person conceptualizes it as the box is one of the items that you're allowed to use, you use the thumbtack, you stick the box to the wall, you put the candle in, sticking out of the box, and you're done, right? But if a person has not been primed for that, many, many, many of them will fail to even think that they can use the box in this experiment. I mean, like, there's tons of studies that I think that where this, there's this thread of computationally, we just can't think of everything at once.

[00:34:24]  Bruce: And so being primed makes some sort of difference. And I think I would take that away from this maybe otherwise, you know, bullcrap experiment, that it's still getting at something that's true. It's still getting at something that's useful and that I would want to know about, right? And when I think of it in that way, it's part of the growth of knowledge, even if the individual study is only indirectly doing that. You know, there's nothing I can take away as a specific law of human nature here. That doesn't matter so much as the realization that priming my brain makes some sort of difference.

[00:35:02]  Brian: Yeah, and so I'm glad you used the word or phrase law of human nature because it sparked to mind something I did want to mention. And we don't have to linger on it. It's just something I thought about. So the philosopher Bryan Magee wrote a short book about Popper, and I think this is where he said this. And I don't believe he was referencing a direct quote from Popper. I think he was just sort of describing his thoughts on something. And we talk about, you know, physical laws, or laws in physics rather, that you take the speed of light or something, you know, of that nature. And, you know, we, it, I think in some ways, it matters how we think about them and whether we think about them as descriptive or proscriptive. So, you know, if you think about a law like a speed limit, the law says, you know, you shall not go past 55 mile an hour. Prescriptive.

[00:35:59]  Brian: Here's what you are going to do. But at least unless I'm misremembering what Magee sort of described, there was reason, at least from Popper's point of view, to view them as descriptive. That, you know, the speed of light describes the fastest moving thing that we have yet observed. But I don't know that necessarily means that, you know, if we happen to find something moving faster than the speed of light, we should then conclude it's supernatural, right? It's natural. It's simply moving faster than light. So you have now found the upper limit of, you know, how fast something can move in the universe.

[00:36:38]  Bruce: Well, one obvious thing that would mean, let's say we actually did find something moving faster than the speed of light. That would be a problem for a very hard problem for general relativity, right? It's a falsification. I kind of hesitate to use that term because I don't think, I think it's a little bit misleading.

[00:36:58]  Unidentified speaker: I understand.

[00:36:59]  Bruce: It's more a problem. It will become [unclear: possibly “falsification”] once we have a new theory. But right away, you know, oh, my gosh, there's something wrong here, right? And we need a new explanation. Now, maybe that new explanation turns out to be, oh, I didn't connect my cord correctly and the instruments off, right?

[00:37:18]  Brian: Absolutely. In fact, I believe that's happened.

[00:37:20]  Bruce: That's happened.

[00:37:21]  Unidentified speaker: Yes.

[00:37:22]  Unidentified speaker: Something.

[00:37:22]  Brian: And that's maybe that's why that example came to mind, because I think at one point it was purported that a particle was observed to be moving faster than light only to find out that it was just a problem with the instrument.

[00:37:35]  Bruce: The cord, yeah. Deutsch mentions that in one of his papers. That's actually how I knew about it.

[00:37:40]  Brian: I should have assumed that.

[00:37:43]  Peter: Can I ask you a question, Brian?

[00:37:44]  Unidentified speaker: Yes.

[00:37:45]  Peter: Well, just to give you a little bit of background, Bruce and I released, well, we spoke for six hours, I think a lot more than six hours, in what I think are some of the most interesting conversations I've ever been a part of. Trying to sort of rectify this idea that on one hand, humans are universal explainers, and goes along with this idea of universality. And Bruce really helped me understand a lot more about the implications on that. And on the other hand, what seems, I don't know, kind of obvious a little bit to both of us, which might not be obvious to a lot of fans of David Deutsch, but seems kind of seems true to me, is that people are kind of born with the abilities, with certain abilities, I guess, or temperaments, or however you want to put that, and this idea of IQ. Well, okay, so to David Deutsch, or at least many fans of David Deutsch, ability and IQ is just a matter of time and interest, okay?

[00:39:13]  Peter: Which is...

[00:39:13]  Bruce: Even for severely mentally challenged cases.

[00:39:16]  Peter: Yes, which makes, I think, a lot of sense in a theoretical way. But, you know, like I said, I'm a special education teacher. I have a lot of, like, real world experience that brains are quite hard to change, or minds, however you want to think about it. What do you think, Brian? I mean, is that an interesting point on this more theoretical perspective on humans being universal explainers? Is that worth thinking about in your research?

[00:39:49]  Brian: So, I think there are a few ways to approach answering that. Other than, yes, it's very interesting. And then I think in an important sense, it doesn't do as much damage to the idea of studying individual differences or, you know, cognitive abilities, intelligence, personality. It doesn't really harm that as much as it may seem at first blush. And I'll give you at least a couple of examples of why I think that's the case. I don't know if it will be persuasive at all, but we'll give it a shot. So, to start out in a very basic sense, let's not talk about universal explainers, let's talk about universal blood pumpers. Kind of weird, right? But our species, homo sapiens, is required to, you know, it's part of our evolutionary lineage. Blood is a vital part of our ability to live, and thus we need it pumped all over our body. And barring some type of sort of medical anomaly or developmental disorder, all humans are born with hearts that pump and function.

[00:41:09]  Brian: So if we were to try and, say, do a twin study on the heritability of having a heart, there is no heritability of it. There's zero, because heritability is a calculation of, related to variance or variation in a population. And so in this twin study of having a heart, heritability is going to be zero. And if there are individuals in the population who do not have them, for whatever reason, they're going to not have them because of some environmental factor. They had an accident. They have a severe illness, something along those lines, right? So in that sense, you know, it doesn't, when there are universal features of a species, two eyes, two legs, two arms, it doesn't make sense to talk about heritability in the context of what we do in twin studies. Because if there's variation in the number of arms that humans have, typically that's due to environmental intervention, maybe either via accident or the necessity to amputate a limb or something like that.

[00:42:17]  Brian: So I don't have any problem with, there can be universal features of an organism that aren't heritable where you have to be careful with language though concerns things that can vary in a population even for universal features. So if we return to the heart, we all have hearts, but there's a lot of variation in terms of how those hearts function and the capacity that they have to pump blood, pump efficiently, to avoid disease states, those types of things. And still there are things in the environment that create that variation, but that is an opportunity for heritable variation to be a factor as well. And so another example we might talk about are, you know, well, we can go to some type of cognitive personality trait. And we can, I'll, I'll, I'll hesitate for some reason, but we'll just linger on it for a second. Take something like intelligence.

[00:43:15]  Brian: It's such a, part of the reason I don't want to linger on it is such a fraught topic, unfortunately, but there is such a rich body of evidence. And it's not from one field. It's from multiple fields, neuroscience, neurobiology, medicine, psychiatry, you know, and for a variety of reasons that, you know, to understand, you know, measures of intelligence as capturing, you know, sort of intuitive ways that the brain is functioning, speed at which messages are relayed, processing speeds, you know, the effects of things like myelination on nerve cells, those types of things. You see the sort of the those skills erode as you disrupt key brain circuits. You see, sadly, you know, in patients with dementia or, you know, disease that cause lesions in the brain that disrupts these things. So but the brain is a good example because, I mean, for a twin study of having a brain, the heritability is zero, right?

[00:44:22]  Brian: Everybody has one. But if we start to talk about then, say, a structure that can vary, and these studies have been done, whether it's a structure of the hippocampus or some cortical feature or problems with Broca or Wernicke's area that lead to language delays, these things can all vary, and they vary for both heritable and environmental reasons. And so my only point is universal features are not at odds with individual differences. And the larger reason they're not is that we, like our primate cousins and rest of the natural world, at least if we take sort of a materialist, naturalist view, which is the one I hold, is that we have an evolutionary lineage and history. And all of our assemblages, our physiology, our organs, our cognitive capacities, all of those things are the product of evolutionary forces, whether that's natural selection, drift, byproducts of other adaptations, whatever it might be, is in that umbrella, under that umbrella of evolution.

[00:45:33]  Brian: And so these are just concepts that are necessary when you talk about animals that evolved via natural selection and other processes. So that's why I just don't perceive any real problem with these things.

[00:45:51]  Unidentified speaker: Thank you.

[00:45:53]  Unidentified speaker: Absolutely.

[00:45:53]  Brian: I don't know if I answered your question or said anything persuasive, but I appreciate you raising it.

[00:45:59]  Bruce: So I think the key thing here, though, is that the fact that human beings are universal explainers, we're assuming that theory is true for the moment, it does raise a particular problem. Whereas if I see social sciences as being about trying to understand human nature, human nature could be a moving target very easily because of the fact that we are universal explainers.

[00:46:30]  Unidentified speaker: Sure.

[00:46:34]  Bruce: So I actually agree with everything I just said there, but it seems like I can't then use that to say there's no such thing as human nature. And let me explain why. So let's say that I start with something really basic. I'll talk with fans of David Deutsch, they'll say there's no such thing as human nature and because we're universal explainers, blah, blah, blah. And I'll say something like, and genes cannot influence us, something they often bring up, which, you know, tons of science showing that that's not the case. And I'll say, okay, can the pain influence you, right? Like, do you not like to be in pain? And I mean, like, the answer is kind of obvious that, yes, you are influenced by pain and you don't like it because it's unpleasant and it hurts. And then I'll say, okay, that is evolutionary psychology right there. And it's an example that we all know is true, right?

[00:47:33]  Bruce: It's that is human nature. And then they'll say they'll do something like this. They'll say, oh, but there's this guy, he works at the circus and he likes pain because he gets paid for it. Or maybe he's a masochist. And they'll try to find an exception case. And I'll say, look, I'm just looking over the population, right? Do human beings in general dislike pain? And even those counter examples you give me are not straightforward, right? Even Gandhi did not like pain, right? I'll say this really kind of is a hard law of human nature, at least at our current level of knowledge. You might convince me that it won't stay that way. You know, we learn to develop drugs that shut off pain and we figure out how to do that. And so then people don't mind going to surgery because they can shut the pain off. And yes, that knowledge from our universal explainership can even modify how we interact with pain and may someday entirely remove pain as a source of suffering.

[00:48:31]  Bruce: Okay, but we're not there today. So at least as of today, I can talk about evolutionary psychology or human nature, and I can talk about it being directed by the genes because it's the genes that wire us this way. And it makes perfect sense. And even if you tell me it's not going to be that way a hundred years from now, it does not change that it is that way today.

[00:48:55]  Brian: This is a, I hate to jump in too fast, but this is a good, actually, I'm glad you mentioned pain. This is a good example to make a kind of the same point I was raising earlier. So, and there are a variety of points to make. One, let's set aside whether pain is always adverse or unenjoyable or to be avoided or constitute suffering. I think psychologist Paul Bloom made this point in a recent book. Sometimes we actively seek out discomfort and perhaps even minor suffering in the pursuit of something else that we want to achieve, whether that's a hard physical workout or a taxing academy to get into a certain profession or military training.

[00:49:41]  Bruce: By the way, they always raise that as an issue. Hey, I go, I enjoy pain when I'm working out. See, that proves that as a universal explainer, I can rethink pain in a different way. So, yeah, sorry, go on.

[00:49:55]  Brian: I would agree that there's a cognitive element to the interpretation of pain. We're capable of saying it's not just our body flashing pain and demanding a counter response. We have the cognitive experience of knowing that this pain is not dangerous. This pain is from bench pressing 10 times. And so I don't need this. There's no medical care to be sought. There's no fight or flight response that need responding to. There is nothing wrong. And in fact, this is pain sought out. But there are other things to remember too. And one is related to earlier. We also we know that there's individual variation in susceptibility to pain, enjoyment of pain, all of these types of things. So that's one where we talk about, one, a universal of having pain, and two, variability in the experience, which can be partly heritable, is partly heritable. Then the third thing is this is sort of an important point of consideration from, you know, world medicine.

[00:51:01]  Brian: There are rare cases where individuals are born without the ability to feel pain, and I'm blanking on the medical name for it at the moment. But this is not something to be wished for in this sense, because these folks lived very difficult lives and often died tragically young for very minor things because, you know, it may be they were in a car accident and didn't realize they were bleeding internally, and so didn't seek medical help until it was too late. So the absence of pain and the danger of that also in some ways points to the importance of it. And sort of the so it may not be that aversion to pain is a law of human nature, but it might be more defensible to say something like attending to pain is part of our nature kind of thing.

[00:51:54]  Peter: Can I read a tweet from David Deutsch real quick that I just think is so relevant here? Keep in mind, this is probably an area of his philosophy that I'm a little bit like kind of like I've hinted at before. I'm probably the most I don't want to say disagree with, but maybe he just takes a little too far. But I still am influenced by it and find it very interesting. But he says, the phenomenon of genetic influence as conceived by most people doesn't exist. A pessimistic mixture of correlation equals causation, anthropomorphism of genes, behaviorism, and ignoring creativity. An unusually strong inborn fear of heights may cause or prevent a love of skydiving. I thought he really lays it out there, I think.

[00:52:47]  Bruce: That's the most clear-cut statement I've heard from him. I kind of gathered that's what he believed, but that's a very clear-cut statement I don't think I've seen before.

[00:52:56]  Brian: It may seem a little ironic. I don't disagree at all. But with this proviso, I suppose, so maybe, I mean, so Deutsch might view this as me disagreeing with him, although I don't think that it really is. So, for example, we talked about this when we chatted about twin studies. Simply doing a twin study and finding a trait to be partly heritable should be, I mean, it should be interpreted as it is, which is, in a sense, associational, correlational. You're explaining variance, right? But that doesn't mean you're saying that genes are causing anything. But that also, nor does it mean that it's impossible to do those types of studies. There are designs that allow you to do them. In animals, you can do them with knockout studies. In people, we're obviously, there are very understandable ethical constraints on how we study these things. But that doesn't mean that can't be done.

[00:53:56]  Brian: In fact, some very interesting ways of doing them involve combinations of twin studies and genome-wide association studies that are used to develop what are called polygenic risk scores. And you sort of combine those two things, and you are able to start to calculate sort of causal effects in the a la Judea Pearl's framework of graph theory and path analysis, those types of things. And so I don't know that we want to make strong arguments about genes not being able to cause it. But I also have a sense that maybe that's not what he's saying and could be pointing to confusion that folks have about the very thing that I try to caution students about this when, you know, maybe sitting in an intro class with me or learning about this for the first time, there are no direct connections of genes on behavior in the way that a simplistic understanding might lead you to think.

[00:54:49]  Brian: And I don't mean simplistic pejoratively. I just mean someone coming new to the topic. It's a very, very, very long chain of causality to get from genetic variation to some phenotype, assuming that chain of causality is even present. We have to do the hard work to find that out. But it's going to, you know, it will have to traverse, you know, some version of a sequence from, you know, base pairs and DNA to either regulating the expression of other genes or, you know, it could be a gene that varies in the type of protein it produces when it strings its amino acids together or codons together. So the point is, at least, you know, for folks who work on this topic, we'll use what's probably an unfortunate shorthand and say something like, you know, violence is heritable. There aren't genes for violence. And so, but at the same time, people could be absolutely forgiven for thinking that that is what we're saying, because we're using sort of jargon that can at times be confusing.

[00:56:02]  Brian: But the idea of overcoming a fear of skydiving, yeah, absolutely. But that doesn't, that also doesn't originate out of the ether, right? There are personality styles like we all have a fear of height. Some of us are more, you know, if we think in terms of classic Big Five personality, openness and extroversion are two probably pretty key traits. If we score high on a measure of openness and that we're always seeking novelty and same with extroversion, always seeking novelty, new experiences, it may scare the holy hell out of you to look out the door of that plane at whatever height you're at and then fling yourself out of it and pull the ripcord. And then it may be intensely fun. You do it again, but I can promise you this. My personality is such that if I'm jumping out of the plane, it's cause the plane's crashing. Even then, I'm going to try to land it first.

[00:56:54]  Brian: So I'm terrified of heights. And I also would probably not score high enough on any of the key metrics to warrant wanting to try and overcome them. So that may be the one quibble I'd have with the example is that, you know, decisions to overcome sort of maybe these evolved phobias. I think, yeah, absolutely they exist. There are some folks who have, you know, pet snakes, and you could cogently argue there are reasons we have to fear things that are predatory and have been in our past, but aren't now. And they overcome them all the time. Steven Pinker has a very famous example from The Blank Slate, and he's making this point that sort of I'm trying clumsily to make about there being no reason to fear genes as deterministic influences and thus try to fight against arguments that we perceive to say that. Steve said something along the lines of, you know, my selfish genes, alluding to Dawkins' famous book, may be doing everything they can possibly do to drive me to reproduce, but I've decided that, you know, a family is not something I want, so my selfish genes can go jump in the lake, right, to sort of paraphrase.

[00:58:14]  Brian: He's right, of course, but I mean, so if that, but if that's the version of genetic determinism you're pushing back against, there's no need because there's no reason to think it.

[00:58:27]  Bruce: So can I use my own example here for a second? Give some, Peter's right, we talked about this in several episodes, so I'm going to be slightly summarizing what we talked about in those episodes. Let's use fear as the first example, because that's probably the closest to what I sense David Deutsch wants, or at least the fans of David Deutsch want the truth to be, okay? That fear is something that's, quote, unpleasant, but because we're Universal Explainers, it's not that hard for us to really get a thrill out of it and turn it into something we enjoy, which is why people go see horror movies or why I play horror VR, which my wife thinks I'm mad, that I intentionally go into a VR haunted house and get haunted and I'm scared to death, and that I actually find that thrilling, right? And she can't even understand where I'm coming from, right? So from a certain point of view, I completely agree with the Deutsch fan viewpoint that because we're Universal Explainers, It is not as straightforward.

[00:59:35]  Bruce: The genes can simply tell us, you will find fear unpleasant, and so you will avoid things that cause fear. That is impossible for the genes to do to a universal explainer. Now, having said that, it would be wrong to say, therefore, because of this, universal explainers are not influenced by genes. And that's what I keep taking exception to. First of all, my wife will not, and probably never will, learn to enjoy going into VR and being scared. So there is only a certain percentage of people who do decide to go skydiving and get a thrill out of it, and would get a thrill out of it. Now, it's because of that you have to then explain, why does not everybody want to go skydiving? Why does not everybody—why is it only a small percentage of people who want to go skydiving or go into VR horror, and that there's so many people who it is just not for them?

[01:00:35]  Bruce: Well, yeah, that's genetic influence. Genetics can influence universal explainers, and we're seeing it right there, even with the fear example. I still think the fear example is maybe too easy. So let's go back to the pain example, okay? Yes, it's true that when I back before I had my health problems, and I used to work out, and it would be painful to work out, but you would enjoy it, and you would enjoy that signal of pain, and you would look forward to working out because you knew it meant it was going to make your muscles larger, and it would give you these health benefits. And so you had this explanation that allowed you to enjoy pain. So you can't say pain is just unpleasant. I don't know that I buy that argument. It's kind of true. But the truth is, is that first of all, it was hard to learn to work out in the first place, because you have to go through several days of pain that lasts for several days.

[01:01:33]  Bruce: Even though I had an explanation for why it was there and I was going to get past it, I had to wait. It really wasn't enjoyable for me until I got to the point that I was doing it often enough that the pain would go away within a very short order.

[01:01:46]  Unidentified speaker: Right?

[01:01:47]  Bruce: Because as you start to exercise, the pain starts to be something that's, it goes right away, right away. Whereas at first, it will linger for days. And during the period where it lingers for days, it didn't matter that I had an explanation, oh, I'm going to feel good in the long run. I still hated it, right? It is still a very unpleasant experience. And then secondly, working out pain just isn't a very good example because I've experienced kidney stones. And if I had to go through the level of pain that I go through with kidney stones each time I worked out, I promise you no one would choose to work out, right? There are levels of pain so severe that there is no way to reconceptualize it as an enjoyable thing. It just can't be done, or at least it can't be done by the vast majority of human beings. Let me say that and I'll leave a little bit of an out because who knows, right?

[01:02:40]  Peter: I think David Goggins would still work out, but...

[01:02:45]  Bruce: And obviously, part of this is how tolerant you are of pain, you know, things like that. But kidney stone pain, I don't think anyone can really just tolerate it at its height, right?

[01:02:56]  Unidentified speaker: It's...

[01:02:57]  Bruce: there's what I call above the line and below the line. There's a certain amount of pain that you can be in where you can just ignore it. And because of that, you can more easily conceptualize it as enjoyable. And then there's this above the line pain that I've experienced, where I promise you no amount of reconceptualization through your universal explainer module is going to cause you to start enjoying this pain. It is not possible, right? And if I were to give maybe the most obvious example of this, it would be women and labor. Here you have the ultimate example of something severely severe form of pain equivalent to kidney stone pain. And also it's being reconceptualized, right, because you know that you're doing this to give birth. And yet you really won't find women who say, oh, I totally enjoy labor pain, right? It just does not exist.

[01:03:55]  Bruce: Like even ones that don't get epidurals and want the, quote, full birth experience, they go do things to try to reduce the pain as much as possible. They get into a bathtub and they go to great lengths and teach classes on this because there is no way to take labor pains and simply re-imagine them as enjoyable because they are above the line. And at this point, the genetic influence that has been put inside you, at least for most people, maybe you could overcome this with lots of meditation or something, but at least for most people at their current level of knowledge, the genes are going to force you to think about nothing but that pain because it's so unpleasant. And so I don't really find the pain example a good example. I think it's the type of example that a person who's never had labor pain or kidney stone pain would use, but anyone who has would go, oh, yeah, you know what, you're totally full of bullcrap with that example.

[01:04:52]  Bruce: And that's kind of how I see it, right? Is that there's kind of some truth to it, clearly to a degree, as universal explainers, we can we can choose to look at unpleasant experiences and imagine them as pleasant. But I don't think that that's a full explanation. I think that there absolutely are situations where it's so severe that the genes are going to win. Like when I'm in kidney stone pain, I don't think there's much of anything I can do at the least at the height of the pain, other than think about the fact that I have a kidney stone, which is what the genes want me to be doing.

[01:05:26]  Unidentified speaker: Right.

[01:05:27]  Bruce: And I actually went through a whole semester where I was in kidney stone pain for a month. And luckily, it wasn't at the height. So I would be able to take pills and I had to make this choice between, am I going to take tests doped up on painkillers so I can't maybe think very straight, or am I going to take that in pain so I can't maybe think very straight? Luckily, the pain levels sort of went down a little bit. The kidney stone pain tends to start super high and then your body kind of gets the hint and starts to reduce the pain somewhat, but it was still pretty severe. And it was a really tough semester. There was nothing I could do except just accept, I'm going to get lower grades this semester and this is going to be harder for me and I'm going to just do the best I can. And all the teachers work with me, they let me take tests from home.

[01:06:18]  Bruce: This is BYU, they're pretty trusting, amazingly trusting. They would send tests home with me and say, okay, just don't take longer than an hour on this and then give it back to me, you know. And I got through that semester that way and I didn't have to drop out of school due to this kidney stone. But I'm telling you, that was a massively painful experience and it is absolutely pain will force you to think about, make it really hard for you to concentrate on anything else if it's a high enough level of pain.

[01:06:49]  Brian: Yeah, I think those are all really good points and there was one additional thing I wanted to mention. It's going to sound sort of only tangentially related to what you just discussed. But I think it turns out it's a relevant point of consideration and it also relates to sort of unfortunate misunderstandings when we talk about genetic influences on things. So I think there are a couple studies that come to mind that are good examples. So, one, they show how twin studies mesh so well with other arenas of scientific science and medicine or psychological science, excuse me, and medicine and those types of things, which was a theme in the Nature paper of ours, we discussed Nature Reviews paper. And so in a couple of particular studies I have in mind, these folks were looking at sort of the functional connectivity between the areas in the prefrontal cortex of the brain and the amygdala, sort of the interplay, inter-exchange that exists and is facilitated by these cortical structures being able to talk back and forth with these limbic structures.

[01:08:00]  Brian: And so a lot of folks, it's quite common for folks to have heard, at least heard of the amygdala in the past, it's been called the fear center of the brain, that's a pretty bad oversimplification, but it's certainly involved in threat, circuitry, threat awareness, awareness of things and has some part, something to do with the experience of fear, which we've been talking about. And so when you like, when you study why people differ in the nature of the functional connectivity of the frontal cortex and these limbic structures, they do differ, is the first thing to think about. Yes, they have Amygdalas, yes, they have a prefrontal cortex. So in that regard, they're not different. But in the regard to the nature and degree and functional connectivity of those regions of the brain, there are differences. And so that then allows you to ask the question, what explains the differences?

[01:08:58]  Brian: And so when you do twin studies, what you find is that it's on average that these functional differences that exist are moderately to small, heritable estimates that emerge with a lot of variance being consumed by the environment. But the bigger point is this. These are the types of things. There's no magic effect that genes are having. The genes are doing their jobs in terms of taking care of, in this case, the creation and wiring of brain circuitry. But that doesn't mean knowing that these differences, knowing that their functional connectivity exists a certain way is going to tell you every time what someone is going to want to do. But at least no one that I'm aware of is making that argument. This is simply a small step forward in understanding how our brains, what is happening when we make decisions, feel emotions, these types of things.

[01:09:57]  Brian: But it's one of those things that just but one step forward. But I think it matters because we don't, I don't think we want to go too far in the direction of thinking that something magical happens when a human makes a decision. And by too far, I mean thinking that our brain's uninvolved with that. I think the better, more defensible understanding is that as we understand more about how brains operate, why the structures of the brain differ from person to person, why the functionality differs from person to person, we'll understand better how decisions are made, what decisions are made. But then the element that I think is also important is, and folks like Pinker and maybe Deutsch have pointed this out, when our species has really amazing things like language, and language is by nature combinatorial, which means you can take a limited number—I know you guys know this—take a limited number of symbols, combine them into what seems like a limitless number of words to convey what feels like a limitless number of thoughts and ideas and arguments, and those can include arguments for why you should or shouldn't do something, why you should enjoy skydiving or not, and those arguments can effectively change the thinking of other people.

[01:11:22]  Brian: So again, it's not mysterious or in some ways, a lot of it's not understood yet, but certainly not magical.

[01:11:31]  Bruce: Okay, let me actually, Peter, let me go. Let me have you go first. Do you have any questions?

[01:11:37]  Peter: I think my questions have kind of monopolized the time a little bit. I know there's stuff you want to talk about, Bruce, so why don't you go?

[01:11:45]  Bruce: So I do have one last thing that probably will take 15 minutes to discuss. And in the Bruce Caldwell paper, he quotes Popper on the idea that he calls the unity of science, although Popper calls it unity of method. Let me actually read from the Bruce Caldwell paper. I think this is like in the footnotes or something, but somewhere in the paper, he says this. He says, sometimes Popper expresses this point more strongly. In this section, this is quoting Popper now, in this section, I'm going to propose a doctrine of the unity of method. That is to say, the view that all theoretical or generalizing sciences make use of the same method, whether they are natural sciences or social sciences. And then, then Caldwell says a few pages later, though, Popper acknowledges that the use within the social sciences of quote, what may be called the method of logical or rational reconstruction, or perhaps the zero method accounts for perhaps the most important difference between the methods of natural—of the natural sciences [wording incomplete].

[01:12:54]  Bruce: So then Caldwell goes on to say, if the unity of science thesis is to make any sense, I think it is best to interpret it as stating that all scientific explanations share the same structure. This also seems to be the position taken by Popper. So this is something I've given a lot of thought to. And there seems to be drastic disagreements between my read of Popper on this and pretty much every other critical rationalist I have talked to. But when I read Popper, I see him as saying there is one epistemology. It applies to everything. It applies to history, even if you don't think of that as a science. It applies to philosophy. It applies to… and this epistemology is evolutionary epistemology. It applies to science. It applies to social sciences. It applies to even things that you might not think of sciences at all. It applies to how we solve problems, how we come up with ideas, and that it applies to statistical inference.

[01:14:01]  Bruce: It applies to what we now call induction. Induction in this sense is actually just critical rationalism.

[01:14:07]  Unidentified speaker: Okay?

[01:14:08]  Bruce: It's a form of critical rationalism. There are no exceptions. There is exactly one epistemology and it is universal across everything. Now, I have talked to so many people now who read Popper, have read the same books as me, some have read more Popper than me, and there seems to be an almost universal disagreement with me on this. To the point where I've had people tell me, for example, that probability theory has no place in Popper's epistemology. I can like literally quote to them where he wrote a whole chapter on this. I had one person I was doing a Zoom with, and we started talking, and I mentioned probability and Popper's epistemology. He said, no, probability theory plays no role in Popper's epistemology. I go, Popper wrote a whole chapter, chapter eight of Logic of Scientific Discovery about how to integrate probability theory into his epistemology.

[01:15:03]  Bruce: He'd go, that's impossible because there is no way to falsify a probabilistic theory, so it cannot be part of Popper's epistemology. I go, but he wrote a whole chapter on it. You should be like, go look up the chapter, go, nope, that's impossible. And it was a really funny conversation. I have funny conversations like this all the time. There seems to be a very wide opinion that Popper was talking about something far more narrow and that it doesn't apply to everything. So I wanted to maybe talk with you about that because it seems like that's relevant to what you're talking about, is we have these other areas, social sciences, softer sciences, economics. And at some level, I do see Popper as saying even economics must fall under critical rationalism. It must be ultimately that it's a form of critical rationalism, even if at first it seems like it's doing something else or doesn't seem to fit well.

[01:16:00]  Bruce: And I do think that that's a problem. Like I've really struggled with how to make sense of... I did a whole series of podcasts on Donald Campbell's theory and his attempts to unify Popper's epistemology across basically everything. And I found counter examples to it. I came up with three different counter examples, one of which turned out to be false. Vaden showed that I was wrong on one of them. But the other two seemed to be correct. And I've never really felt like I fully understood how to integrate this idea of the universe, unity of science that I see Popper as believing in across absolutely all things that I would consider knowledge creation or science or whatever. And I feel like this is an extension of the problem, that it's a little hard to figure out how to apply it to, say, economic.

[01:16:52]  Unidentified speaker: Thoughts on that?

[01:16:53]  Brian: It’s a great—it’s a great point. And it's a lot of fun to think about too. I don't know. Again, I'm going to do my best. But I won't contend that I have my final answer, even a good one. But so this is sort of how I've been thinking about it. So I think to make the point I would want to make, I would start with actually something more in the legal sphere of things, not even necessarily academia. Think about a criminal trial and presume in this instance that we don't have anything like closed circuit television catching someone robbing the store, okay? Someone's been arrested for this burglary and we highly suspect that the person that has been arrested actually did commit the burglary. We've got no way to verify it, nor does the jury, obviously have a way to, we can't put on the closed circuit television and show them the person breaking into the store.

[01:17:52]  Brian: So, we have to build a case by sifting through relevant evidence, keeping what seems relevant, discarding the rest, and then using that to make our argument, knowing that at the end of the day, you can always come back and say, well, you can't prove it, well, you're right, I can't. And so, there's something important there that I think is worth keeping in mind.

[01:18:18]  Bruce: I agree, good example.

[01:18:20]  Brian: Yeah, then we go to something like economics or political science or things of that nature. Let's say we do a hundred studies testing some esoteric idea in economics, about price theory or something like that, and we get a very, very consistent pattern of results and all those things. These are really robust studies. On one hand, you haven't proven any law of economics, and I think my response would be, of course, we [unclear: “have it”]. That's not what we're doing. We're retaining what looks like we're conjecturing and trying to refute, and until we can get something that looks a lot like a refutation, and we have to know and remember that to get that, that's an iterative process. One study is not going to do it. A hundred might not do it, but I think it's feasible to, at least in practice, reject something. But we're not getting at truth.

[01:19:18]  Brian: We're getting at provisional knowledge that we've tried to sift through all of the nonsense to get to the things that look a lot less like nonsense. And I think that also can be part of the difficulty in terms of creating consternation about how to make these things work is we often don't think about all of the de facto wrong explanations that we never even bothered to test because they're so obviously wrong, we wouldn't devote our time to, right? Like we would never argue that price theory results from people who eat tomatoes and then desire to overspend on a particular commodity or something bizarre like that. It's just that's a non-starter. It's never tested. And so there is a wasteland of bad ideas that we just assumed to be that, right? And so we don't even bother with those, and we try and run through what at least seem to be intuitively good explanations for whatever it is we're trying to explain.

[01:20:16]  Brian: But I think the heart of what, and I'm not arguing Popper said this, this is maybe more my read of it or my extrapolation of it, is that the heart of what unifies these things is conjecture and refutation. You know, we propose ideas, we test them, and we reject them if the need arises. But until that need arises, we retain them, knowing all along that we haven't proved anything, but we're not in the business of proof. We're in the business of better explanation.

[01:20:46]  Unidentified speaker: Yeah.

[01:20:47]  Bruce: Well, okay. I don't really disagree with anything you just said, but let me give you some troublingly hard cases, as troubling as I can make them on the fly here.

[01:20:57]  Brian: Absolutely.

[01:20:58]  Bruce: So let's use the example of a courtroom case.

[01:21:01]  Unidentified speaker: Okay.

[01:21:02]  Bruce: So it's easy for me to say a courtroom case takes the form of conjecture and refutation.

[01:21:08]  Unidentified speaker: Okay.

[01:21:09]  Bruce: But when you really look at the way we do a courtroom case, what you really do is you try to find corroborating evidence. You try to say, okay, I can place this person that they had the typical motive means and opportunity, that they had a reason they wanted to do this, and they could have been available at the time. And in a lot of cases, we talk about circumstantial evidence. People use the term circumstantial evidence as a negative. Well, that's just circumstantial evidence. But the vast majority of cases and convictions come from circumstantial evidence, right?

[01:21:45]  Brian: At least to some degree, yes.

[01:21:47]  Unidentified speaker: Yep.

[01:21:47]  Bruce: Yeah, I guess you would know that. I've listened to a lawyer podcast where they claimed that. But you would probably know even better than lawyers would.

[01:21:55]  Brian: No, I wouldn't claim any more expertise, but I think that's a reasonable point.

[01:21:59]  Unidentified speaker: Yeah.

[01:22:00]  Bruce: So the fact is, is that what we're really trying to do doesn't fit super comfortably into even conjecture refutation. It's not like it's directly at odds with it. You are conjecturing this person did this. But then you're not really trying to refute that they did it. You're actually trying to find evidence that they did that verifies that they did.

[01:22:24]  Brian: I think I might stop you briefly enough to argue that I think the defense team is absolutely trying to refute it.

[01:22:31]  Bruce: That is true. That is a fair point. The defense team is going to try to find evidence that this person could not have done it. For the sake of argument, let's take the point of view that this person, that there is nothing, there is no alibi available, which is very common. What we're really left with is that there is no way to refute that this person didn't do it because they have no alibi. But we're still going to have this standard of innocent until proven guilty. We're expecting something to take place. We're expecting there to be, even though we know we're never going to refute, we're never going to refute the theory that they did it. And that's impossible, in fact, in this case. So what we're going to do is we're going to strengthen the theory. There's that word again, and we're going to find support. There's that word again, for the fact that this person probably did it.

[01:23:31]  Bruce: There is that word again, right? Words that cause Popperians to just go, you know, angry with mad and say, that's all Bayesian, right? And yet those aren't terrible words in a courtroom case, right? We are looking for supporting evidence. We are looking for something that kind of verifies in some sense that this person did it. Now, I do think it is possible to take everything I just said, where I'm intentionally wording it in ways that would get Popperians mad. And I think it is possible to come up with some way to put that in negativist terms. I just did an episode on defense of corroboration where I did claim there are no words, positivistic words that you can't then restate in a negativistic way. But sometimes it's really inconvenient to do so.

[01:24:20]  Peter: Well, I really loved the way you put that in that episode, how you said that you made the comparison to Newton's laws versus general relativity, where on an everyday basis, it might be perfectly reasonable for a scientist to use Newton's laws, just as it may be useful to talk about probabilities. But on a deeper, more fundamental level, if you really want to get into the nitty-gritty, Newton's laws are wrong, general relativity is right, just as critical rationalism is right. So that kind of really rang true for me to parse out the difference.

[01:25:04]  Brian: Just quickly, maybe just because you guys might be able to correct my understanding, that's kind of how I've thought about some of the key points that Popper made in regards to a lot of these bigger issues, which was very much akin to the Newton relativity example. It's not that you can't calculate, say, the travel of an object, like an artillery shell or something using Newtonian mechanics.

[01:25:30]  Unidentified speaker: You can.

[01:25:31]  Brian: You can do it. You can do it. You could do it the day before Eddington took those pictures, and you could do it the day after. But the foundational explanation had to change. And so sort of as an analog, I don't know that Popper said thou shalt not think inductively about anything that it never matters, that it's never useful, that those concepts are forever irrelevant. I just understood him to mean that the broader picture, the deeper thing that we're doing, is something different.

[01:26:04]  Bruce: Yeah, that's my point of view, too, by the way. And that was actually what I argued in my episode on corroboration. I think sometimes it's hard, though. I gave the example of we invent a time machine, and when we invent this time machine, we claim that the time machine goes back in time, and it follows exactly what David Deutsch says in Fabric of Reality. We create a new universe, a new world, a branching timeline, and now we have this time machine that lets us move between the two worlds. How can you say that this doesn't strengthen the theory of many-worlds interpretation of quantum physics, if we're now able to actually test for these other worlds and show that they exist through verification, right? I mean, of course it does. So I suggested if you want to put this into a Popperian framework of conjecture and refutation, you have to give it some thought, because it's not obvious at first how to do it.

[01:27:03]  Bruce: And I quoted David Deutsch how he would go about this, which I thought was a really good answer from David Deutsch, and he suggested that in a case like this, you would have to understand it as there's theories that don't yet exist, nascent conjectures of how to try to explain quantum physics without many worlds. And now that you actually have another world you can see, those all just died, even though they aren't even yet true theories. And so to put it into a negativist framework requires you to realize that you can refute a theory that doesn't exist, which is a mouthful, right? And I think that's exactly correct, though, is that you can put it into a conjecture refutation framework, but that it is often quite difficult to figure out how to do so.

[01:27:51]  Brian: I think that's really good and helpful. And I agree completely. Yeah, absolutely.

[01:27:57]  Bruce: And I think something similar is going on with my court case example. It's outside the bounds of anything I can be like. I've been wanting to do an episode where I talk about how to put court cases into a critical rationalist framework, because I think you can, right? But I intentionally just put it in a way that I think would be typical of how people would think of it. And I don't think they're wrong. I think that when they put court cases in terms of reasonable doubt and how sure you are and, you know, is there enough evidence that there's a high probability and I have supporting evidence, I think that that's a really useful way to speak. And I'm not about to tell them, oh, that's all wrong because that's false epistemology.

[01:28:37]  Unidentified speaker: Right.

[01:28:38]  Bruce: I think that that's a super useful way to speak about court cases. And I don't think that any of those terms are going away anytime soon.

[01:28:46]  Unidentified speaker: Right.

[01:28:46]  Brian: And I agree. I think there, if nothing else, it's an intuitive way to use language. And in some cases, the bigger point is you want to, especially in a legal setting, you want to make sure the jurors understand their instructions. You want them to make decisions in accordance with how the law says they should, which is, in this case, the only thing I would change in the thought experiment is, I would argue that the conjecture is that the person is innocent, meaning that's the starting point. You've got to refute the conjecture that they didn't do it, because that's where we're starting. And if the prosecution does a poor job, then they're going to fail to refute that conjecture, whether they may have supporting evidence or not. And then that's another place where, like you described, I think it's perfectly cogent to talk about. So this is an extremely bad example of bad evidence, but just imagine that part of the prosecution's case was, well, look, we know this to be certain, that the defendant did not buy any international travel tickets, they did not cross any—either the Canadian or Mexican border during the—on the night that this happened.

[01:30:03]  Brian: So we know that the person was in the United States and capable of committing crime X, and this is part of our evidence. It's not going to be enough to refute the argument that they're innocent.

[01:30:14]  Unidentified speaker: I would imagine.

[01:30:15]  Bruce: Yeah, I think that this is something that requires a lot of more careful analysis that we're not going to probably get into in this episode. I know David Miller has written some excellent articles about this that I would like to cover maybe in a future podcast. But I think it is entirely possible to take court cases and put them into a critical rationalist framework, but I think it's very counterintuitive, and you really have to give it some thought how to do it, and that it just more naturally fits into a positivistic framework. And I think the reason why that's true is for exactly what Peter was quoting me on, because positivism isn't entirely wrong. It's kind of a simplified version of critical rationalism that is like Newton's. It's sometimes right and it's sometimes wrong. But it's often easier to think of it in a more positivistic way because it kind of matches our intuitions in a lot of cases.

[01:31:13]  Unidentified speaker: Sure.

[01:31:14]  Brian: Yeah, I don't disagree. It's fun to talk about, too. I think it's more than just a sort of a passive intellectual exercise. I think it's really useful to try and think through these things because it clarifies, at least for me, it provides ever more clarity in how best to think about what I do and it's my day job as a scientist. So I enjoy that.

[01:31:37]  Bruce: All right. Brian, thank you very much. I would love to have you on the show again sometime. I think that you've been one of our best guests and I can see that the three of us have really similar thoughts on a lot of things. It would be nice to get your take. And just having access to a working scientist who's working on these very thoughts in a real field where it is somewhat difficult to know how to apply Popper's epistemology to it. I think that's just phenomenal.

[01:32:07]  Brian: Well, that means a lot to me that you said that. I really appreciate it. And I will come back as often as you all will have me. And at any point, if you get bored with me, that's perfectly understandable as well. It happens to students all the time. But thank you. It really has been a pleasure. And I appreciate you guys inviting me.

[01:32:27]  Bruce: All right.

[01:32:27]  Unidentified speaker: Thank you.

[01:32:28]  Peter: Thank you, Brian. This is wonderful.

[01:32:30]  Unidentified speaker: Thank you.

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[01:33:47]  Unidentified speaker: Thank you.