Derek Parfit - Rational Irrationality
Peter, Fraser and Nick discuss the thought experiments of Derek Parfit.
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Transcript
Hello and welcome to the Cognitive Engineering Podcast produced by Tell Me Studios for Aleph Insights. In this series of podcasts we take a look at interesting topics and discuss what we think they tell us about analysis and decision making. I'm Fraser McGruer and I'm here with Nick Hare and Peter Coghill of Aleph Insights and this week we're discussing the philosopher Derek Parfit and rational irrationality. So Nick, can you lead us in please?
Speaker B:Yeah, so the reason we're talking about this now is that Derek Parfit died a few weeks ago in January and he wrote a lot of very interesting things, did a lot of interesting work on some of the things which we're interested in in Aleph Insights, particularly about decision making and what constitutes good decision making. And he wrote in particular, one of his most influential books was called Reasons and Persons and it goes through a long series of short chapters, each of which takes a specific claim or runs with a particular thought experiment. And some of them are really bonkers, these thought experiments, but all of them are designed very rigorously to test various theories about how we ought to behave, what kinds of rules we ought to follow, what it means to say that we're the same person as we were yesterday, which turns out to be very closely related to the issue of sort of good decision making. A lot of his thought experiments are about personal identity. It's a very famous thought experiment involving a transporter where you get destroyed on earth and exactly reconstituted on Mars and the question of whether or not you're the same person, which turns out again to be very important to thinking about when we make decisions about our future selves, how much should we care about our future selves? How much are they the same as us? Anyway, very influential philosopher, even he looked the part, he had a sort of big shock of crazy looking hair, but he was extremely rigorous and very influential. But we want to talk about one specific thing he looked at, which was this issue of, so some of the things he looked at were to do with sort of what are called dynamic decision problems. So where you have to make decisions, which affects you over time. So usually decisions where you're looking at a situation right now and the effect will be immediate are usually quite straightforward, but they get much more complicated when you start thinking about potential future consequences. So in particular- Give us an example. Yeah, so he talked about an example which had also been raised by Schelling, who was a game theorist, where being rational, so rationality in philosophy and economics terms simply means, well it means that you try and make your beliefs true, right? So you want to believe true things about the world and you want to take actions which get you what you want to achieve. So you want to take actions that will deliver the things you want. Now that seems like a very uncontroversial claim, right? So the right thing to do is to do things that will deliver what you want. So that's a claim that says being rational is good, right? Because being rational, following the rule that you should always try and do things that get you what you want is better. But he talked about a potential counterexample, where a robber comes into your house and threatens you, threatens that he's going to murder your family unless you give him the- The keys to the safe, was it? Well, yeah, I was going to say the combination. So threatens to murder your family unless you give him the combination to the safe. And obviously the right thing to do here is to give him the combination to the safe. That's in the short term what you want. You'd rather, and he knows that you're going to respond to that threat because you'd rather lose the money in the safe but keep your family safe. But Parfit said, well, wouldn't it be better to have a kind of irrationality potion where you could take the potion and you no longer cared? You could just sort of say, well, you can threaten me all you like. I'm not going to give you the combination of the safe. You can go and kill my family. I don't care. And if the robber knows that, then he knows he can't threaten you. He can't rely on your rationality to get what he wants and you
Speaker A:end up better off. Yeah. I mean, doesn't something like this happen in actually happening in the natural world where what's his face talks about it in what's his face, the famous botanist. So Nigel, what's his face? Yeah, I think it's Richard Dawkins. The selfish gene. Right. And in that, I think one of the things he talks about is it's actually quite good to be a balance in an animal of something that may or may not attack. You don't want to be the kind of animal that will always attack and the one that will never attack. You want to be one where no one's ever quite sure what you're going to do. I'm not sure. That is exactly bang on. Yeah. So
Speaker B:it turns out that a lot of the tools economists develop to look at human decisions and human interactions can be applied really powerfully to evolution. And game theory has got lots of explanations for apparently weird behaviour in the animal world and particularly self-sacrifice. So when animals fight to the death, the point is that it's better to be the kind of animal who will fight to the death, even though at the point at which you're going to be threatened, it would be better to run away. Yeah. So and the reason it'd be better is because other animals won't stay away. Yeah, well, exactly. So and that's and game theory kind of proves that there's an optimal equilibrium where you sort of sometimes fight to the death and sometimes don't. But also
Speaker A:you could, maybe there's two different types of rationality here, because one where you're purposefully being irrational, because you can, because it makes sense to run away. But actually, it's a nice strategy to purposefully be irrational. But sometimes you could just be irrational without reason, as it were. Yeah, well, it's hard. You can't actually be
Speaker B:deliberately irrational. That's that's one of the sort of weird things. You can't choose to be irrational, unless you are somehow completely preventing yourself, you have to impose a constraint on yourself in order to stop being rational. That's the that's the weird thing. You can't choose to be irrational, if you could actually at some point choose to stop being irrational, because then you would just take the short term benefit, you know, you would you would
Speaker A:give the robber the combination. So I mean, I presume of everything we've been talking about five minutes now, of everything. I mean, that's a platform, because I doubt we've said anything there, which is groundbreaking. It's more of a summary, right? So let's sort of try and develop this a little bit. And Peter, what have you got to say at this point? Well, I mean, I'm not a I'm
Speaker C:an engineer, not much of a philosopher. So I've really got some questions for Nick to explore this a bit more. So presumably, presumably, it changes if you have this, the game with the robber and the safe is repeated frequently, presumably, there's a more of a repeated game
Speaker B:changes the nature of the balance. Well, yeah, I mean, so one of the one of the biggest challenges, I think, to the kind of old conventional idea that if we all behaved in our self interest, we'd be better off, you know, the kind of traditional view that follow everyone following their self interest will all gradually push us towards a world where we're all better off, right? That's kind of classical economics assumption, completely undermined by the prisoners dilemma. I think we've discussed that before the prisoners dilemma. Yeah, but it but it's a situation where two people following their self interest, make the end up all worse off. And there's loads of examples of that, you know, the kind of examples from real world stuff like overfishing, where you know, it makes each person has an incentive to catch as much fish as they can. But if everyone does that, then there's no fish left. And, you know, and all the fishermen go out of business. That's a tragedy of the common. Yeah, exactly. Tragedy of the commons is a kind of multiplayer version of the prisoners dilemma. So now when you put when you when you have a repeated prisoner, prisoners dilemma against against the same player, you open up other other kinds of solution where you can actually end up cooperating. So again, it's one of these things where when you have a dynamic element, when you have repeated games, when you add time to the thing, you end up with lots of other potential solutions. One of which is is is cooperating, you know, and then basing what you did on what the person did last time. I'm not sure exactly how that applies to the
Speaker C:situation. How does it sort of happen? Then another question I have is how does it how does it apply, if at all to negotiation practice and theory? So assuming that there's some opportunity for dialogue between the robber and the the Robbie, is there a is there a is there a because they're majoring on what they're they're talking about what they really want. So that you're the bit hasn't been robbed is saying, Oh, I don't want my family killed. And the robber saying I want the money in the safe. But if there were if there was other scope for negotiation, does that does this
Speaker B:does that link to this? Yeah, I mean, that's a negotiation is where like, it's probably the place where real life game theory happens the most. So people actually do use game theory, because I'm
Speaker C:thinking of where in negotiations, you would concentrate on the minutiae of things, and not talk about the big issues to to, to conflate and confuse your opponent.
Speaker B:Yeah, actually, that's, I mean, and that's one of the findings from from sort of the game theory analysis of negotiation is what you should do is pretend to care about the things you don't care about, and pretend not to care about the things that you really do care about. Because then you can then you can make a what in your, from your perspective is a very small sacrifice, look like a big sacrifice and extract concessions from it. But yeah, I mean, so so negotiate is another classic example where it would be better to seem irrational. There's other analysis of kind of games, like where you have a trade union, for example. So trade union wants to be able to make a sacrifice it wants it saying that we're going to actually impose a cost on ourself to try and gain some kind of advantage in negotiations. They want to seem irrational, they want to look like they would be willing to go on strike, you know, for ages and ages to cost the company lots of money. Now, if they're being really rational, they just wouldn't, you know, in some circumstances, they wouldn't. And you can see that a lot international negotiations, people want to look like they're being irrational, they want to look like they're going to bullheadedly ask for something. And if they don't get it, you know, they're going to just pull the trigger. And yeah, I mean, that's, that's something that... So can we turn this to, I mean, something that
Speaker A:might be interesting is just apply this to the current political, international political environment. Can we hang this off something, any current negotiations or any current international issues going on at the moment? Yeah, I think we can probably think of one. We can because, yeah,
Speaker B:I mean, well, there's obviously is Brexit where we, you know, there's quite a lot of debate, wasn't there, about why don't we tell everyone what our negotiating stance is, you know, Parliament moaning a bit about wanting to see what the plan was. I mean, you definitely don't do that. And things like the, you know, the EU nationals being in the UK, a lot of people, you know, well-meaning people saying, oh, we should take that off the table. You know, we should just say, yes, it's fine if they stay here. Well, that's terrible negotiating strategy. Because it's something that we do have control over, which the EU will care a lot about. So we definitely, you know, but actually, it's also interesting to think about the personality types of leaders, like someone like Putin, or Trump. I think people have drawn an analogy between them by the fact that they are very, they're not utilitarians. They're not going to sit there and go, hmm, well, the best thing to do here would be to back down. They're very sort of victory driven. And you want to look like you care about winning at all costs. If you're in an international negotiation, monopolizing the irrational card. Yeah, that's the interesting thing.
Speaker A:Well, this reminds me, it makes me think a lot of the two games of poker and chess. Because something like poker is you definitely want people just to go, what the hell is this guy doing? And you know, and that's why it can be difficult sometimes playing against a fairly novice poker player, because they tend to sort of be overconfident. And they tend to go all in too much. And you never know, is it just because this guy's really got a great hand? Or are they a total idiot? And similarly, in chess, I'm, I've, when I used to play chess quite a lot, I actually never became a particularly good player. But I used to find it and it's quite well documented, you know, playing a quite a new chess player can be quite difficult, because they do some very
Speaker C:odd things. Responding weird ways. Yeah. But there's a fundamental difference between those games, because chess, you have all the information. Whereas in poker, there's obscured information.
Speaker B:Sort of, although I mean, there is the problem that actually in practice, you don't really in chess, because it would be computationally unfeasible to compute the consequences of any given move. So there is there is uncertainty there. Different kind of uncertainty. Yeah.
Speaker A:But I'm sorry, I'm probably sort of slightly taking a soft track from my question about the international environment at the moment. So we talked a little bit about Brexit, we talked about Trump and Putin. Peter, anything you want to bring in at this point? Well, I mean, maybe we
Speaker C:maybe we could explore towards what's the optimal strategy? So is it potentially an optimal strategy is to be able to appear to be irrational when it best suits you. So being able to sort of message in the right way that you're irrational, whereas your your actual decision making process is still
Speaker B:entirely rational. Yeah, I mean, we you want the so I just take it in a slightly engineering direction, not necessarily for Peter's direction, for Peter's benefit, but because it's interesting is I don't know if you know about the Russian perimeter system. No, but I'd like to. Well, it's a system called perimeter and sometimes called a dead hand firing system, which is designed to look for whether or not there's been a nuclear war. The principle being that if the all the decision makers in Moscow were knocked out, they would still want to be able to retaliate. Now this is so this was this is a similar it is actually is it like the doctor strange? It's exactly it. Yeah. So that this is actually true. So the Russians did have this system. And I'm not sure it's known whether or not it's still active. But where you know, they would they would be kind of automatic sensors looking for radiation, seismic activity, looking for signs of a nuclear war. And if they detected it with no humans in the firing chain at all, they would just launch a massive retaliation. Now, that's brilliant from a from a sort of strategic point of view, because there's you completely removed a rational response because, you know, most people think the rational response to being attacked with nuclear weapons is just to suck it up and go, well, we've lost. You know, there's no point in making the world worse by retaliating. But what you really want is the opposite of that you want you want to be able to retaliate with 100% you know, with a with a 100% probability, because then the other side won't
Speaker C:start a nuclear war at all. Yeah. So does it undermine or strengthen the mutually assured
Speaker B:destruction balance? Yeah, well, the downside is that it what if it goes wrong? Yes, quite a lot of faith in the system not not going wrong. And as we all know, from lots of examples throughout sort of nuclear diplomacy, there have been quite a few near misses. We don't know how near because, you know, we saw them when they got stopped. But so that that's, you know, as usual with these real life things, you know, you the all of the kind of game theory does slightly go out the window when you're dealing with real life systems, because of the uncertainty about how they'll actually perform. Where do we go from here? That well, I do want to this is I'm trying to I'm trying to get a piece to talk about systems, but particularly, like systems where you take human decision making out. So at the moment, for example, we have we have drones that always have to have a human deciding whether to fire right. But it will be a lot scarier, wouldn't it if they were designed to fire automatically? When they saw certain, you know, examples of, of sort of terrorist type activity or whatever. And I mean, the question of the question of how much you design for humans, and, you know, autonomous vehicles, it's the same thing. If you if you design autonomous vehicles, so that they always swerve when they see a person in the road, then people will just blithely wander about in the road when they in perfect certainty,
Speaker C:they won't get run over. You get Yeah, you get a sort of safety system. Effect where seatbelts make people drive faster. And more recklessly. Yeah, no, well, I think I think it's fair to say that it's going to be the human in the loop where all the mistakes will come from. However, they all they they they they are also the place that has as in the ability to accommodate new information that's not in this predefined pre programmed way of working that will cause a nuclear fire chain to to to to activate. But so it I suppose it's there's some sort of balance required as to how much risk if of getting it wrong when you want it to want something to happen versus it going wrong because the computer is just it's computer says fire computer says fire computer says yes, when when you probably didn't want you there's an additional bit of information that can't be accommodated in that decision. The human would say the human on the firing chain, perhaps in the submarine would just not fire because he knows something that the computer
Speaker B:can't take account of. Yeah, I mean, the UK's policy, if you can call it that is to not have is to not tell anyone what our policy is when it comes to nuclear retaliation. So we deliberately maintain this strategic ambiguity, right up to the very, to the very top really in that the I think one of the things that Peter Hennessy talks about is the first job of any prime minister is to write down orders for the submarine commanders for the nuclear submarines, you know, the submarines carrying nuclear weapons about what to do if if you know the UK gets taken out by a nuclear strike. And so no one knows no one ever looks in those envelopes and they're destroyed.
Speaker A:At the end of that Prime Minister's tenure. I hope that doesn't end up like the moment comes and the submarine commander opens it up and goes la la land. Well, yes, but I think I think well,
Speaker B:I think right maybe making this up. I think Harold Wilson said that his his orders were to just sort of go to Australia and find a nice beach somewhere, which is a completely sensible. I mean, you want what you want is for the Russians to think that you've written down, you know, massive retaliation against Moscow. But actually, actually, when the push comes to the shove, you don't want that to be the case, because that would just make things worse, you know. Peter, I mean, we've still got
Speaker A:a few minutes left. But anything to say before I wrap up? No, no, no. Well, one thing, one thing,
Speaker C:just to try to explore perhaps more comedically this example. So is it the you've you've got this option of taking this potion to make you genuinely irrational? Is there not a danger, then that the robber might be able to convince you to open the safe anyway? Yeah, I mean, actually, what you what
Speaker B:is really about is stopping yourself being able to take actions. I mean, being unconscious would be perfectly good. Taking a taking a taking a potion that just knocked you out for two hours would be just as good. It's really about cutting off your ability to take options. And I mean, that's, that's the that's the paradox, really, is that sometimes it's better to stop yourself being able to have a choice, which is which is, you know, counterintuitive, because you think, well, actually, that surely being taking the optimal, the optimal option, every point in time is going to be better. But the point about this example, and one of the things that Parfit talked about a lot was that sometimes it isn't, that really throws a spanner in the works, actually, when we when we think about how we ought to behave, it makes it makes the world much more confusing and more interesting, and more difficult to manage. But I mean, it does. But does it does
Speaker C:that mind? Does that thought experiment also assume that the robber has some put some sort of value on human life that he won't kill you just out of revenge or annoyance? Because you've, you've, you've, you've swung the game in your favor? Yeah, I think the assumption is that
Speaker B:the robber would sort of very slightly prefer not to have to be a murderer as well. Yeah. But the point is that if you're being rational, he doesn't have to be. He doesn't have to have to be a murderer, because you're going to open the safe. Right? Yeah. Okay. So yeah, but actually, so
Speaker A:actually, that's interesting, because that requires the robber to be rational, right? And I'm just wondering what happens if you get to get an irrational robber and an irrational Robbie?
Speaker B:Yeah. Nightmare. Total, utter breakdown of everything we hold dear. Maybe the robber ends
Speaker C:up walking away with the kids. And yeah, live happily ever after. The other guy locks himself
Speaker B:in the safe or something. Yeah, that's probably what that's probably what the outcome would be.
Speaker A:Very briefly, slightly off topic. What do you think are the largest irrationalities that you have in your day to day lives? Because I know I mean, one of mine is probably I mean, I mean, I started trying to think of one and I realized there are many but one of them was probably smoking of you know, and it goes back to what we're saying with I always want to say Rick Parfitt. But with with Derek Parfitt, Rick Parfitt, for anyone who doesn't know, was or is one of the lead guitarists of the amazing... Didn't he die recently? Yeah. Yeah. Well, that's why I get confused between the two, but of the legendary rock band, heavy metal rock band status quo. But anyway, yeah, and it ties in one of his things about, I think what we were saying about identity and future selves is that I used to used to annoy me when I smoked, because I knew that was such a bad thing for me. And it made me question or how much do I care about my future?
Speaker B:Yeah, well, I mean, that's that's a good example where which is the real Fraser, right? Is it smoking Fraser or Fraser who wants to give up smoking? And the whole point about trying, you know, doing using tricks like throwing away your cigarettes or, you know, or taking even just just taking nicotine patches or even telling people, you know, I'm going to give up smoking are all ways of constraining your future self. Because future Fraser gasping for a fag. It's a different person. He's got different goals. And your goals right now might be to give up smoking. And you've got you're playing a game against future Fraser whose goals are to carry on smoking. And you basically you're playing this game against yourself and you want to win. So you're going to make it make life hard for future Fraser. Of course, future Fraser is going to be really annoyed with past Fraser because he wants a fag. And he may well try and rig things so that when regretful Fraser turns up again, you know, he won't be able to. So yeah, I mean, there it is something that crops up all the time. It's a very,
Speaker C:very common situation. And there are some places that are kind of there are external systems to help you impose those constraints. So a pension scheme is a way of locking money away that you would otherwise, you know, you might otherwise spend at the end of the month. Because you know, when you sign up to a pension scheme, it's a good idea. So past you made this decision for future you to stop you from spending all your money.
Speaker B:Yeah. But I think my I'm in terms of the things that we've been talking about, I am a real grudge merchant. I do bear I bear grudges for years. There are particular there is there are certain teachers that I will I'm still out to get somehow. And when the chance comes, I will. You know, so I mean, that's that's completely irrational. Some at sometimes, you know, people who just perhaps slight you on the tube. A couple of weeks ago, Blake barged past me on the bus instead of saying, excuse me, I I'd happily, you know, kill that guy. So kind of, you know, annoying. And that's that's the kind of, you know, reptilian brain, rational irrationality, which which means that, you know, people don't mess with me. Unfortunately, I don't know that when they're on the bus. Sure. That's it. Now he won't
Speaker A:make that mistake. You need to paint yourself like yellow and black or something. So people
Speaker C:don't stay away. Yeah. Yeah, exactly. Peter, I suppose. I mean, I like wearing nice leather shoes and an awful lot go out wearing a shirt. And I know that's really mad. I know it really doesn't matter what I look like. I could go out in trainers and jogging pants and it wouldn't matter what I looked like by and large. But I kind of like to feel like maybe some people think I look smart, even though that doesn't matter at all. Sounds like that's a rational response to other
Speaker B:people's irrational desire to make other people wear nice shoes. I think I think, you know, ties.
Speaker A:We've talked about ties a lot. But I think you should start with a haircut then if you're going to don't worry about the shoes. And I would mean I had a haircut two weeks ago. This is this is short. It's funny, actually, I've been thinking about doing something similar to what you've said, which is I spend most of my time working from home and I just slob around in any old rubbish. And I just I'd like I'd like the thought of my children as they growing up and actually once they're grown up thinking back to this, to their father. Oh, yes, he was always so smartly dressed in a nice jacket and a shirt. Always wore a waistcoat at home. Right? Yeah. And I think I need to start doing this because and also for my own sense of self worth and and belief in what I am that I need to be starting to doing that. I don't know if that's rational or irrational, but but all I would say is I don't want to end up being regretful Fraser, which I quite like that characterization. We're going to have to stop there. So, gentlemen, I enjoyed that. Thank you, as always, to Nick Hare and Peter Coghill of Aleph Insights. You've been listening to the Cognitive Engineering podcast. I'm Fraser McGruer. Thank you. And until next time. Bye bye. And thank you to Derek Parfitt for his excellent works. And thank you to Derek Parfitt, rocking all over the world.
