WEBVTT - Ep76 "How do you decide?" (Part 2) 0:00:05.080 --> 0:00:08.039 How do brain's time travel. We all know what a 0:00:08.119 --> 0:00:10.760 prediction is, but why is the important thing to the brain? 0:00:11.119 --> 0:00:14.040 What's called a prediction error? And what does any of 0:00:14.080 --> 0:00:16.239 this have to do with the two thousand and eight 0:00:16.400 --> 0:00:20.279 crash of the economy, or how we keep internal price 0:00:20.400 --> 0:00:23.600 tags on everything, or what we should do with the 0:00:23.640 --> 0:00:30.440 war on drugs. Welcome to Inner Cosmos with me David Eagelman. 0:00:30.560 --> 0:00:33.599 I'm a neuroscientist and an author at Stanford and in 0:00:33.640 --> 0:00:37.839 these episodes we dive deeply into our three pound universe 0:00:38.200 --> 0:00:41.440 to uncover some of the most surprising aspects of our lives. 0:00:41.760 --> 0:00:52.280 Today's episode is part two about decision making, so let's 0:00:52.320 --> 0:00:55.279 quickly summarize last week's episode to get ourselves back up 0:00:55.280 --> 0:00:58.320 to speed. In that episode, we saw how the brain 0:00:58.440 --> 0:01:03.160 is a sophisticated decision making machine. It's constantly engaged in 0:01:03.640 --> 0:01:07.560 choosing among options. Now, this can be something trivial like 0:01:07.600 --> 0:01:10.960 deciding between a taco and a burrito, all the way 0:01:11.000 --> 0:01:14.800 to life altering decisions like whether to take that job 0:01:14.920 --> 0:01:19.360 or whether to propose marriage. Now, while early economists assumed 0:01:19.400 --> 0:01:23.520 that humans make decisions rationally by weighing pros and cons 0:01:23.560 --> 0:01:27.319 to arrive at the optimal choice. Modern day psychology and 0:01:27.360 --> 0:01:31.320 neuroscience reveals a pretty different story and what we saw 0:01:31.480 --> 0:01:34.039 last week, and something I've talked about before here a 0:01:34.040 --> 0:01:38.400 lot is that the brain is composed of multiple networks, 0:01:38.600 --> 0:01:42.720 each with its own goals and desires, and these often 0:01:43.000 --> 0:01:47.039 compete with one another to influence the decisions that we make, 0:01:47.600 --> 0:01:51.960 and this internal conflict is at the heart of how 0:01:52.000 --> 0:01:55.720 we navigate the world. And by the way, the massive 0:01:55.800 --> 0:01:59.960 battles under the hood largely occur below our conscious awarenes 0:02:00.560 --> 0:02:03.000 So for example, when you look at a picture that 0:02:03.040 --> 0:02:06.520 can either be perceived as a duck or a rabbit, 0:02:06.920 --> 0:02:10.600 your brain chooses one interpretation over the other, and we 0:02:10.680 --> 0:02:14.360 can measure what's happening in the activity of neurons to 0:02:14.480 --> 0:02:18.240 see how one network wins over the other one. And 0:02:18.320 --> 0:02:20.919 in the case of a picture like that, your interpretation 0:02:21.080 --> 0:02:23.720 goes back and forth and back and forth. Now that 0:02:23.800 --> 0:02:26.799 might not feel like a decision to you, but it's 0:02:26.840 --> 0:02:31.480 the same neural process of having competing networks that are 0:02:31.520 --> 0:02:36.760 fighting for dominance, and the same neural battle is mirrored 0:02:36.760 --> 0:02:40.600 in everyday choices, like when you choose between different flavors 0:02:40.600 --> 0:02:43.000 of a sports drink or whether to take the right 0:02:43.000 --> 0:02:46.800 trail or the left trail. All your options are represented 0:02:47.120 --> 0:02:50.519 by different coalitions of neurons in the brain, and these 0:02:50.560 --> 0:02:55.360 coalitions compete for dominance and the winner determines the action 0:02:55.480 --> 0:02:58.639 we take. And we saw simple tasks like this stroop 0:02:58.800 --> 0:03:03.000 task where you have conflicting information like the word reed 0:03:03.639 --> 0:03:06.120 printed in blue ink and you're supposed to name the 0:03:06.120 --> 0:03:10.040 color of the ink. This highlights the tension between different 0:03:10.080 --> 0:03:13.480 networks in the brain. And similarly, we are always facing 0:03:13.560 --> 0:03:17.240 moral dilemmas like I mentioned the trolley problem last week, 0:03:17.480 --> 0:03:21.320 and this demonstrates how emotional and rational networks can come 0:03:21.360 --> 0:03:24.920 into conflict and it can lead to different outcomes depending 0:03:24.960 --> 0:03:27.960 on which network prevails. And one of the things we 0:03:28.000 --> 0:03:32.200 saw from that was that emotions play a really crucial 0:03:32.320 --> 0:03:37.240 role in decision making. The importance of emotional input into 0:03:37.280 --> 0:03:40.480 your decision making is seen really clearly when people get 0:03:40.800 --> 0:03:44.120 brain injury like damage to the orbit or frontal cortex, 0:03:44.600 --> 0:03:48.480 because then they can't integrate the emotional signals from the 0:03:48.520 --> 0:03:53.440 body into a decision, and that leaves a person paralyzed 0:03:53.440 --> 0:03:57.360 within decision even in very simple situations. So without the 0:03:57.400 --> 0:04:02.000 ability to read these bodily signals which we're providing summaries 0:04:02.040 --> 0:04:06.920 of different options. People struggle to make choices. So the 0:04:07.000 --> 0:04:11.200 brain's decision making process is not a straightforward calculation of 0:04:11.240 --> 0:04:16.120 pros and cons but a dynamic interplay of competing networks 0:04:16.120 --> 0:04:20.520 and emotional signals. Every decision we make from what to 0:04:20.600 --> 0:04:23.240 where in the morning, or which coffee shop to choose, 0:04:23.360 --> 0:04:27.080 or how we respond in a crisis, the choices are 0:04:27.160 --> 0:04:31.080 all the results of this ongoing conflict within our brains. 0:04:31.839 --> 0:04:35.039 Now where we left off last week with seeing how 0:04:35.200 --> 0:04:38.839 each decision involves our past experiences stored in the states 0:04:38.839 --> 0:04:42.320 of our body and the present situation like do I 0:04:42.360 --> 0:04:44.440 have enough money to buy this instead of that? Or 0:04:44.520 --> 0:04:47.560 is this other option available? But there's one more part 0:04:47.640 --> 0:04:51.839 to the story of decisions, and that is predictions about 0:04:52.000 --> 0:04:55.640 the future. So that's what we're going to talk about today. Now, 0:04:55.680 --> 0:05:02.119 across the animal kingdom, every creature is wired to see reward. Now, 0:05:02.120 --> 0:05:03.840 surely this is something you know, but have you ever 0:05:03.880 --> 0:05:09.240 thought about the question what is a reward? At its essence, 0:05:09.360 --> 0:05:13.640 a reward is something that will move the body closer 0:05:14.000 --> 0:05:18.280 to its ideal set points. So water is a reward 0:05:18.760 --> 0:05:22.719 when your body is getting dehydrated. Food is a reward 0:05:23.080 --> 0:05:27.040 when your energy stores are running down. Now, water and 0:05:27.080 --> 0:05:32.839 food are called primary rewards because they directly address biological need. 0:05:33.040 --> 0:05:36.280 But what's super interesting is that human behavior is steered 0:05:36.720 --> 0:05:41.400 by secondary rewards, which are things that predict primary rewards. 0:05:41.440 --> 0:05:46.240 For example, the sight of a metal cylinder wouldn't by 0:05:46.240 --> 0:05:49.480 itself do much for your brain, but because you've learned 0:05:49.520 --> 0:05:53.200 to recognize it as a can of sparkling water, then 0:05:53.240 --> 0:05:55.640 the sight of it comes to be rewarding when you 0:05:55.720 --> 0:05:59.520 are thirsty, and in the case of humans, much more 0:05:59.560 --> 0:06:02.599 than anywhere else in the animal kingdom. We can find 0:06:02.760 --> 0:06:08.640 even very abstract concepts rewarding, such as a political ideology 0:06:09.120 --> 0:06:12.120 or the feeling that we are valued by our local community, 0:06:12.400 --> 0:06:15.920 and unlike other animals, we can often put these rewards 0:06:16.040 --> 0:06:20.760 ahead of biological needs. As my colleague Read Montacu points out, 0:06:21.240 --> 0:06:25.200 sharks don't go on hunger strikes. In other words, the 0:06:25.240 --> 0:06:28.599 rest of the animal kingdom only chases its basic needs, 0:06:28.960 --> 0:06:34.480 while only humans regularly override our basic needs. In deference 0:06:34.600 --> 0:06:39.480 to abstract ideals, concepts that we have decided are rewarding 0:06:39.520 --> 0:06:44.120 to us. So whenever we're faced with different possibilities, we 0:06:44.200 --> 0:06:49.640 integrate internal and external data to try to maximize reward. However, 0:06:49.760 --> 0:06:52.720 reward is defined to you as an individual. Now here's 0:06:52.760 --> 0:06:56.120 the point I want to make. The challenge with any reward, 0:06:56.279 --> 0:07:01.080 whether basic or abstract, is that choices to typically don't 0:07:01.200 --> 0:07:05.440 yield their fruits right away. We almost always have to 0:07:05.440 --> 0:07:09.160 make decisions in which a chosen course of action will 0:07:09.320 --> 0:07:12.920 yield reward at a later time. People go to school 0:07:12.920 --> 0:07:16.320 for years because they value the future concept of having 0:07:16.400 --> 0:07:19.880 a degree, or they slave through decades of work that 0:07:19.920 --> 0:07:22.840 they don't like with the future hope of a promotion. 0:07:23.560 --> 0:07:27.480 Or you push yourself through painful exercise with the goal 0:07:27.600 --> 0:07:30.760 of being fit in the future. Now to understand this, 0:07:30.880 --> 0:07:35.760 let's think about the concept of anticipated reward. To compare 0:07:35.920 --> 0:07:40.720 different options means assigning a value to each one in 0:07:40.760 --> 0:07:46.000 some common currency that of anticipated reward, and then choosing 0:07:46.040 --> 0:07:48.880 the one with the highest value. So let's make this concrete. 0:07:49.040 --> 0:07:51.680 Let's say you have a small window of free time 0:07:51.760 --> 0:07:55.000 and you are trying to decide what to do. You 0:07:55.120 --> 0:07:57.840 know that you need groceries, but you also know that 0:07:57.880 --> 0:07:59.640 you really need to sit down and get that big 0:07:59.680 --> 0:08:03.160 email I'll sent off, and you're also way behind on 0:08:03.280 --> 0:08:06.880 arranging to meet with your friend at the coffee shop. Well, 0:08:06.880 --> 0:08:10.640 these are all very different things groceries, email, friend. So 0:08:10.840 --> 0:08:15.280 how does your brain arbitrate this menu of options. It 0:08:15.320 --> 0:08:19.000 would be easy if you could directly compare these experiences 0:08:19.080 --> 0:08:23.040 by living out each one and then rewinding time and 0:08:23.080 --> 0:08:26.120 finally choosing your path based on which outcome was best. 0:08:26.560 --> 0:08:29.000 But the mummer is that you can't travel in time, 0:08:30.320 --> 0:08:36.679 or can't you? In fact, human's time travel daily time 0:08:36.760 --> 0:08:42.080 travel is what the human brain does relentlessly. When faced 0:08:42.120 --> 0:08:47.360 with the decision. Your brain simulates different outcomes to generate 0:08:47.440 --> 0:08:51.400 a mockup of what your future might be. We call 0:08:51.480 --> 0:08:55.520 this time traveling. Mentally, you can disconnect from the present 0:08:55.600 --> 0:08:59.640 moment and voyage to a world that doesn't yet exist. 0:09:00.280 --> 0:09:03.560 Now simulating a scenario in your mind. That's just the 0:09:03.559 --> 0:09:08.080 first step. To decide between the imagined scenarios. You try 0:09:08.120 --> 0:09:12.320 to estimate what the reward will be in each of 0:09:12.400 --> 0:09:18.080 those potential futures. So when you simulate filling your pantry 0:09:18.120 --> 0:09:21.280 with the groceries, you feel a sense of relief at 0:09:21.320 --> 0:09:27.000 being organized and avoiding uncertainty. Finishing that email carries different 0:09:27.040 --> 0:09:30.440 sorts of rewards, not only the primary reward of maybe 0:09:30.440 --> 0:09:33.520 securing some money as a result, but more generally, the 0:09:33.920 --> 0:09:38.160 kudos from your boss and a rewarding sense of accomplishment 0:09:38.200 --> 0:09:41.679 in your career. Now you can also imagine yourself at 0:09:41.679 --> 0:09:45.280 the coffee shop with your friend, and that inspires joy 0:09:45.360 --> 0:09:49.000 and a sense of reward in terms of relationships and 0:09:49.040 --> 0:09:53.800 closeness with other people. So your final decision between these 0:09:53.880 --> 0:09:59.040 three options will be navigated by how each future stacks 0:09:59.160 --> 0:10:02.800 up against the other others in the common currency of 0:10:02.840 --> 0:10:06.440 your reward system. Now, this choice isn't easy, because all 0:10:06.480 --> 0:10:11.720 these valuations are nuanced. The simulation of the grocery shopping 0:10:12.040 --> 0:10:15.880 is accompanied by feelings of tedium, and your simulation of 0:10:15.880 --> 0:10:19.679 writing the long email is attended by a sense of frustration, 0:10:20.280 --> 0:10:23.520 and your simulation of your friend at the coffee shop 0:10:23.600 --> 0:10:26.880 is accompanied with guilt about not getting work done. But 0:10:26.960 --> 0:10:30.280 in all these cases, under the radar of awareness, your 0:10:30.320 --> 0:10:34.040 brain simulates all these options one at a time and 0:10:34.120 --> 0:10:38.720 does a gut check on each and that's how you decide. 0:10:38.800 --> 0:10:43.199 But here's a question, how do you simulate these futures accurately? 0:10:43.640 --> 0:10:46.520 How can you possibly predict what it will really be 0:10:46.800 --> 0:10:50.440 like to go down these paths. The answer is that 0:10:50.480 --> 0:10:53.760 you can't. There's no way to know that your predictions 0:10:53.800 --> 0:10:57.559 will be perfectly accurate. Your simulations are only based on 0:10:57.600 --> 0:11:01.560 your past experiences and your current model of how the 0:11:01.600 --> 0:11:05.000 world works. The key business of brains is to predict, 0:11:05.040 --> 0:11:08.600 and to do this well, we need to continually learn 0:11:08.760 --> 0:11:11.480 about the world from our every experience so that we 0:11:11.520 --> 0:11:14.679 can make the best guesses that we can. So in 0:11:14.720 --> 0:11:18.000 this case, you place a value on each of these 0:11:18.200 --> 0:11:22.560 options groceries or email or coffee shop, based on your 0:11:22.800 --> 0:11:27.280 past experiences and using the Hollywood studios in your mind, 0:11:27.679 --> 0:11:31.720 you travel in time to your imagined futures to see 0:11:32.120 --> 0:11:35.240 how much value they'll have, and that's how you make 0:11:35.440 --> 0:11:40.000 your choices. You compare possible futures against one another. That's 0:11:40.000 --> 0:11:45.080 how you convert competing options into a common currency of 0:11:45.200 --> 0:11:49.840 future reward. So think about your predicted reward value for 0:11:49.880 --> 0:11:53.880 each of these options like an internal price tag that 0:11:54.080 --> 0:11:58.680 stores how good something will be. Because grocery shopping is 0:11:58.720 --> 0:12:01.280 going to supply you with food, say it's worth ten 0:12:01.360 --> 0:12:06.000 reward units, and writing that stupid email is difficult but 0:12:06.240 --> 0:12:09.760 necessary to your career, so it weighs in at twenty 0:12:09.840 --> 0:12:13.320 five reward units, and you love spending time with your friend. 0:12:13.520 --> 0:12:17.040 So going to the coffee shop is worth fifty reward units. 0:12:17.679 --> 0:12:22.120 But there's an interesting twist here. The world is complicated, 0:12:22.200 --> 0:12:26.240 and so your internal price tags are never written in 0:12:26.440 --> 0:12:31.439 permanent ink. Your valuation of everything around you is changeable 0:12:31.720 --> 0:12:36.520 because quite often our predictions don't match what actually happens. 0:12:37.160 --> 0:12:42.800 The key to effective learning lies in tracking this prediction error. 0:12:43.240 --> 0:12:46.760 The prediction error means the difference between what you thought 0:12:46.880 --> 0:12:50.400 was going to happen and what actually happened. In the 0:12:50.440 --> 0:12:54.319 case of this decision about groceries or email or coffee shop, 0:12:54.640 --> 0:12:58.959 your brain has a prediction about how rewarding the coffee 0:12:59.000 --> 0:13:01.319 shop is going to be. Now, let's say it turns 0:13:01.360 --> 0:13:04.000 out that they have some new snack there, and also 0:13:04.080 --> 0:13:07.000 you run into other friends there and the whole experience 0:13:07.040 --> 0:13:10.839 is even better than you thought. That raises the price 0:13:10.960 --> 0:13:14.199 tag the next time you're thinking about the coffee shop. 0:13:14.720 --> 0:13:18.320 On the other hand, if the coffee is cold and 0:13:18.400 --> 0:13:22.360 your friend is late and distracted, that might lower your 0:13:22.400 --> 0:13:40.840 price tag for the next time around. Now, how does 0:13:40.880 --> 0:13:42.720 this work in the brain? How do you have these 0:13:43.200 --> 0:13:47.600 dynamic internal price tags. There's a tiny, ancient system in 0:13:47.640 --> 0:13:52.520 the brain whose mission is to keep updating your assessments 0:13:52.600 --> 0:13:55.840 of the world. The system is made of tiny groups 0:13:55.880 --> 0:13:58.640 of cells in your midbrain that speak in the language 0:13:58.640 --> 0:14:04.320 of a neurotransmitter called dopamine. When there's a mismatch between 0:14:04.360 --> 0:14:11.000 your expectation and your reality, this midbrain dopamine system broadcasts 0:14:11.040 --> 0:14:14.959 a signal that reevaluates the price point. The signal tells 0:14:14.960 --> 0:14:17.880 the rest of the system whether things turn out to 0:14:17.920 --> 0:14:21.400 be better than expected, in which case you get an 0:14:21.440 --> 0:14:25.560 increased burst of dopamine, or worse than expected, in which 0:14:25.600 --> 0:14:29.040 case you get a decrease in dopamine. And that prediction 0:14:29.440 --> 0:14:32.680 error signal, meaning there was an error in the prediction 0:14:32.720 --> 0:14:35.600 that I had made, allows the rest of the brain 0:14:35.920 --> 0:14:39.720 to adjust its expectations to try to be closer to 0:14:39.800 --> 0:14:44.359 reality next time. So the dopamine acts as an error corrector. 0:14:44.800 --> 0:14:49.200 It's a chemical appraiser that always works to make your 0:14:49.200 --> 0:14:52.920 price tags as updated as they can be. That way, 0:14:53.440 --> 0:14:57.840 you can rank your decisions based on your optimized guesses 0:14:57.880 --> 0:15:02.160 about the future. Fundamentally, what the brain pays attention to 0:15:02.280 --> 0:15:06.920 are the unexpected outcomes, something being better than expected or 0:15:07.080 --> 0:15:10.360 worse than expected, and this sensitivity is at the heart 0:15:10.400 --> 0:15:15.320 of animal's abilities to adapt and learn. It's no surprise then, 0:15:15.400 --> 0:15:19.440 that the brain architecture involved in learning from experience is 0:15:19.560 --> 0:15:23.920 consistent across species. You see this from honeybees to humans. 0:15:24.400 --> 0:15:29.000 In other words, brains discovered the basic principles of getting 0:15:29.120 --> 0:15:33.600 feedback from reward a long time ago. So we've seen 0:15:33.720 --> 0:15:38.040 how values get attached to different options. But there's a 0:15:38.080 --> 0:15:41.160 twist that often gets in the way of good decision making, 0:15:41.600 --> 0:15:44.160 which is that options that are right in front of 0:15:44.200 --> 0:15:48.120 you tend to be valued higher than those that you 0:15:48.200 --> 0:15:52.360 merely simulate. The thing that trips up good decision making 0:15:52.400 --> 0:15:56.480 about the future is the present. I'll give you a 0:15:56.520 --> 0:15:59.680 really interesting example of this. In two thousand and eight, 0:16:00.240 --> 0:16:03.120 the US economy took a sharp downturn. Many of you 0:16:03.160 --> 0:16:06.360 may remember that at the heart of all the trouble 0:16:06.480 --> 0:16:11.080 was a simple fact, which is that many homeowners had overborrowed. 0:16:11.120 --> 0:16:14.160 They had taken out these mortgage loans that had really 0:16:14.200 --> 0:16:16.640 low interest rates for a period of a few years, 0:16:16.800 --> 0:16:19.320 and the problem occurred at the end of that period 0:16:19.760 --> 0:16:23.479 when the interest rate suddenly shot up to something quite high, 0:16:23.560 --> 0:16:27.760 and a lot of homeowners suddenly found themselves facing down 0:16:27.840 --> 0:16:30.800 the barrel of these higher interest rates. And they realized 0:16:31.080 --> 0:16:33.320 they weren't going to be able to make the payments. 0:16:33.880 --> 0:16:38.080 So close to a million American homes went into foreclosure, 0:16:38.120 --> 0:16:42.840 and that sent shockwaves through the economy of the planet. Now, 0:16:42.960 --> 0:16:44.320 what in the world does this have to do with 0:16:44.440 --> 0:16:49.720 competing networks in the brain. Here's what these loans called 0:16:49.760 --> 0:16:54.320 subprime loans. They allowed people to obtain a nice house 0:16:54.720 --> 0:16:59.200 right now, with the high interest rates defferred until later. 0:16:59.760 --> 0:17:04.200 As such, the offer perfectly appealed to the neural networks 0:17:04.200 --> 0:17:07.960 that care about instant gratification. In other words, those networks 0:17:08.000 --> 0:17:11.960 that want things right now. The idea was here, take 0:17:12.000 --> 0:17:15.280 these keys, this house is yours. The mortgage payments are 0:17:15.320 --> 0:17:18.400 pretty easy to make. Oh yeah, the rates will go up, 0:17:18.560 --> 0:17:21.680 but that's a long way away. That's obscured in the 0:17:21.720 --> 0:17:24.200 midst of the future. You don't have to worry about 0:17:24.200 --> 0:17:27.800 that right now. That's a long way off. And because 0:17:27.840 --> 0:17:32.359 of the seduction of the immediate satisfaction, as in, wow, 0:17:32.359 --> 0:17:34.239 I can move into this house right now, I can 0:17:34.280 --> 0:17:37.919 impress my parents and my friends and whatever. Because the 0:17:38.200 --> 0:17:43.160 now pulls so strongly on our decision making, the two 0:17:43.200 --> 0:17:47.080 thousand and eight housing bubble can be understood not simply 0:17:47.160 --> 0:17:50.520 as an economic phenomenon, but as a neural one. And 0:17:50.560 --> 0:17:52.439 by the way, the pull of the now wasn't just 0:17:52.480 --> 0:17:55.000 about the people borrowing, of course, but it's also about 0:17:55.000 --> 0:17:58.880 the lenders who are getting rich right now by offering 0:17:58.960 --> 0:18:02.040 loans that they suspec might not ever get paid. They 0:18:02.280 --> 0:18:05.679 rebundled these loans and sold them off. Practices like this 0:18:05.720 --> 0:18:09.840 are unethical and illegal, but it proved too enticing to 0:18:09.960 --> 0:18:13.960 many decision makers when they were faced with that temptation. Now, 0:18:14.080 --> 0:18:18.160 this now versus the future battle. This doesn't just apply 0:18:18.240 --> 0:18:21.600 to housing bubbles. It cuts across every aspect of our lives. 0:18:22.000 --> 0:18:24.879 It's why car dealers want you to get in and 0:18:24.960 --> 0:18:28.480 test drive the cars, because the seduction of the now 0:18:28.920 --> 0:18:31.640 is probably going to override your thinking about the distant 0:18:31.680 --> 0:18:34.760 future when you have to pay that monthly loan. It's 0:18:34.880 --> 0:18:37.680 why clothing stores want you to try on the clothes, 0:18:37.760 --> 0:18:40.040 because once you see yourself in front of the mirror there, 0:18:40.080 --> 0:18:43.000 you'll think, wow, I can't pass that up. It's why 0:18:43.119 --> 0:18:46.040 merchants want you to touch the merchandise. It's because your 0:18:46.400 --> 0:18:50.720 mental simulations of the future can't compete well against the 0:18:50.800 --> 0:18:54.440 experience of something right here, right now. In your hands. 0:18:55.200 --> 0:18:59.679 In other words, to the brain, the future can only 0:18:59.800 --> 0:19:04.199 ever be a pale shadow of the now. The power 0:19:04.280 --> 0:19:07.119 of now explains why people make decisions that feel good 0:19:07.240 --> 0:19:11.119 in the moment but have lousy consequences for their future. 0:19:11.280 --> 0:19:14.840 So people who take a drink or a drug hit 0:19:15.000 --> 0:19:18.640 even though they know they shouldn't, or married partners who 0:19:18.680 --> 0:19:22.120 give in to an available affair, or athletes who take 0:19:22.119 --> 0:19:25.080 anabolic steroids even though they know it's going to shave 0:19:25.200 --> 0:19:29.800 years off their life. So can we do anything about 0:19:29.800 --> 0:19:33.199 the seduction of the now? Well, with a little bit 0:19:33.240 --> 0:19:37.040 of knowledge about the brain, we can. So consider this. 0:19:37.119 --> 0:19:39.879 We all know that it's really difficult to do certain thing. 0:19:39.920 --> 0:19:43.360 It's like go regularly to the gym. Most people want 0:19:43.400 --> 0:19:45.160 to be in good shape, but when it comes down 0:19:45.200 --> 0:19:47.359 to it, there are usually things right in front of 0:19:47.440 --> 0:19:50.800 us that seem more enjoyable. The pull of what we're 0:19:50.840 --> 0:19:55.600 doing is stronger than the abstract notion of future fitness. 0:19:55.960 --> 0:19:58.720 So here's the solution to make sure you get there. 0:19:59.160 --> 0:20:01.639 You can take in spiration from a man who lived 0:20:01.760 --> 0:20:04.199 three thousand years ago. Now, I talked about this in 0:20:04.240 --> 0:20:06.560 a recent episode, so I'll give the short version here. 0:20:06.600 --> 0:20:09.480 But it's massively important. The man we're going to talk 0:20:09.520 --> 0:20:13.520 about was in a more extreme version of the Jim scenario. 0:20:13.880 --> 0:20:16.800 He had something he wanted to do, but knew that 0:20:16.920 --> 0:20:19.480 he wouldn't be able to resist temptation when the time 0:20:19.520 --> 0:20:23.400 came for him. It wasn't about getting a better physique. 0:20:23.440 --> 0:20:26.560 It was about saving his life from a group of 0:20:26.640 --> 0:20:31.600 mesmerizing maidens. So this was the legendary hero Ulysses, on 0:20:31.720 --> 0:20:35.280 his way back from triumph in the Trojan War. At 0:20:35.280 --> 0:20:38.080 some point on his long journey home, he realized that 0:20:38.240 --> 0:20:41.920 his ship was going to be passing an island where 0:20:41.960 --> 0:20:46.119 the beautiful sirens lived, and the sirens were famous for 0:20:46.240 --> 0:20:51.960 singing songs so melodious that sailors were enchanted. And the 0:20:52.000 --> 0:20:55.119 problem was that the sailors found this irresistible and they 0:20:55.119 --> 0:20:58.800 would crash their ships into the rocks trying to get 0:20:58.840 --> 0:21:02.000 to the sirens, and they would now Ulysses desperately wanted 0:21:02.040 --> 0:21:04.440 to hear these legendary songs, but he didn't want to 0:21:04.480 --> 0:21:07.480 kill himself and his crew, so he hatched a plan. 0:21:08.040 --> 0:21:10.800 He knew that when he heard the music, he would 0:21:10.840 --> 0:21:14.239 be unable to resist steering towards the island's rocks and 0:21:14.280 --> 0:21:18.119 so he recognized that the problem wasn't his present rational self, 0:21:18.440 --> 0:21:23.960 but instead the future illogical Ulysses, the person that he 0:21:24.119 --> 0:21:28.320 would become. When the sirens came with an earshot, so 0:21:28.440 --> 0:21:32.119 Ulysses ordered his men to lash him securely to the 0:21:32.240 --> 0:21:35.040 mast of his ship, and they filled their ears with 0:21:35.119 --> 0:21:37.520 beeswax so it's not to hear the sirens, and they 0:21:37.600 --> 0:21:40.679 rode under strict orders to ignore any of his pleas 0:21:40.760 --> 0:21:44.080 or cries or writhing around. So what was going on here? 0:21:44.240 --> 0:21:47.320 Ulysses knew that his future self would be in no 0:21:47.480 --> 0:21:52.000 position to make good decisions, so the Ulysses of sound 0:21:52.160 --> 0:21:56.159 mind arranged things so that the future Ulysses could do 0:21:56.320 --> 0:22:00.840 no wrong. This sort of deal between your self and 0:22:00.880 --> 0:22:04.479 your future self is known as the Ulysses contract. In 0:22:04.520 --> 0:22:07.760 the case of getting to the gym, my simple Ulysses 0:22:07.840 --> 0:22:11.240 contract is to arrange in advance for a friend to 0:22:11.320 --> 0:22:13.520 meet me at the gym. So then I feel it's 0:22:13.520 --> 0:22:17.439 pressure to uphold the social contract, and that lashes me 0:22:17.560 --> 0:22:21.080 to the mast, even though when the morning rolls around, 0:22:21.119 --> 0:22:22.919 all I really want to do is just sleep in 0:22:23.000 --> 0:22:26.159 or do something else. I've pre arranged a contract and 0:22:26.200 --> 0:22:29.359 now I have to show up when you start looking 0:22:29.400 --> 0:22:32.280 around for these ulysses contracts, you'll see that they're actually 0:22:32.320 --> 0:22:35.000 all around you. Just as an example, I was recently 0:22:35.000 --> 0:22:37.920 giving a talk on a college campus and learned that 0:22:38.240 --> 0:22:42.440 during the week of final exams, some students will swap 0:22:42.520 --> 0:22:46.280 their TikTok passwords with each other, and then each student 0:22:46.400 --> 0:22:48.679 changes the other's passwords so that they can't log on, 0:22:49.240 --> 0:22:52.920 and then when finals are over, they switch the passwords back. 0:22:53.359 --> 0:22:55.679 So this way, during the week that they're supposed to 0:22:55.680 --> 0:22:58.119 be studying, even though they know that they're going to 0:22:58.160 --> 0:23:01.320 be tempted by the sirens song, they can't do anything 0:23:01.359 --> 0:23:05.880 about it. Similarly, the first step for alcoholics in rehabilitation 0:23:06.000 --> 0:23:08.720 programs is to clear all the alcohol out of their 0:23:08.720 --> 0:23:12.040 house so that the temptation is not in front of 0:23:12.080 --> 0:23:16.320 them when they're feeling weak. People with weight problems sometimes 0:23:16.359 --> 0:23:19.760 get surgery to reduce their stomach volume so they physically 0:23:19.960 --> 0:23:23.400 can't overeat. These are all things that you do right 0:23:23.440 --> 0:23:27.480 now so that your future self won't do something that 0:23:27.560 --> 0:23:30.359 you don't want to. It's a way to structure things 0:23:30.400 --> 0:23:33.399 in the presence so that your future self cannot misbehave. 0:23:33.680 --> 0:23:37.360 And that's the trick for getting around the seduction of 0:23:37.440 --> 0:23:40.960 the now you strap yourself to the mast, and that 0:23:41.040 --> 0:23:44.520 allows you to behave in better alignment with the kind 0:23:44.520 --> 0:23:47.879 of person you would like to be. The key to 0:23:47.960 --> 0:23:50.760 a Ulysses contract is just recognizing that we are different 0:23:50.800 --> 0:23:54.800 people in different contexts. The ancient Greeks had a saying 0:23:54.840 --> 0:23:58.080 they liked, which was know thyself. But I've always felt 0:23:58.080 --> 0:24:00.560 from a neuroscience point of view that the the updated 0:24:00.640 --> 0:24:06.480 version is know thyselves now. What's strange is that knowing 0:24:06.520 --> 0:24:09.919 yourselves is not easy because how you act at different 0:24:10.000 --> 0:24:13.159 times is not always something you can predict. Even though 0:24:13.200 --> 0:24:17.240 you can make good guesses, things can drift around. So 0:24:17.359 --> 0:24:20.359 sometimes you're really jazzed about going to the gym, and 0:24:20.440 --> 0:24:24.159 sometimes not so much. Sometimes you'll stick with the diet 0:24:24.240 --> 0:24:27.760 and sometimes you won't. Sometimes you're more capable of good 0:24:27.760 --> 0:24:31.680 decision making, and other times your neural parliament won't come 0:24:31.680 --> 0:24:35.800 out with the vote that you expected. Why it's because 0:24:35.960 --> 0:24:39.879 the outcome depends on a lot of changing factors about 0:24:39.920 --> 0:24:43.080 the state of your body. For example, states, which can 0:24:43.520 --> 0:24:46.000 change hour to hour. So here's a good way for 0:24:46.080 --> 0:24:48.119 us to appreciate this. There was a study done some 0:24:48.240 --> 0:24:52.120 years ago looking at prisoners who are going in front 0:24:52.119 --> 0:24:54.960 of a parole judge to see if the prisoner could 0:24:54.960 --> 0:24:59.720 get his sentence shortened to go home early. So imagine 0:25:00.080 --> 0:25:03.119 two prisoners both scheduled to appear in front of this 0:25:03.200 --> 0:25:06.520 parole judge. One prisoner goes before the judge at eleven 0:25:06.600 --> 0:25:10.040 twenty seven am. His crime is fraud and he's serving 0:25:10.080 --> 0:25:14.720 thirty months. Another prisoner appears at one fifteen pm. He 0:25:14.760 --> 0:25:16.920 has committed the same crime for which he's been given 0:25:17.000 --> 0:25:20.760 the same sentence. Now, the first prisoner is denied parole, 0:25:21.240 --> 0:25:26.520 the second is granted parole. Why what influenced the decision? 0:25:26.640 --> 0:25:29.679 Was it? Race? Was at looks was at age? So 0:25:29.800 --> 0:25:33.320 a study by Jonathan levav In colleagues analyzed one thousand 0:25:33.480 --> 0:25:37.600 rulings from judges and found it wasn't about that. Whether 0:25:38.000 --> 0:25:42.000 the prisoner is granted parole or not isn't just about 0:25:42.040 --> 0:25:46.920 the prisoner. It's about the judge's biology. Specifically, it's about 0:25:46.960 --> 0:25:51.680 the judge's hunger. So just after the judge had enjoyed 0:25:51.760 --> 0:25:56.159 a food break, a prisoner's chance of parole rose to 0:25:56.200 --> 0:25:59.600