The Science of Temptation: Why You Can (or Can’t) Resist

Neuroendocrinologist, Professor of Biology and Neurology at Stanford University
Ever hear the expression "it's all in your mind"? Well, according to Robert Sapolsky all the negativity in the world might all be coming from one part of the brain: the frontal cortex. The science of temptation runs parallel to the science of why people make "bad" decisions. Sapolsky talks about how active the frontal cortex can be in some people when they have the opportunity to do a bad thing... and how calm it can be in other people when presented with a similar situation. Performing full-frontal lobotomies on the world's population to rid the world of negativity isn't exactly in the cards—but understanding the basis of the world's problems on a scientific (not to mention cranial level) might help make future generations much more adept at stopping humanity's biggest mistakes. Robert Sapolsky's most recent book is Behave: The Biology of Humans at Our Best and Worst.

  • Transcript


ROBERT SAPOLSKY: So when we look at the world’s ills one of the biggest sources of it is us failing to do the right thing when it’s the harder thing to do—giving in to temptation, giving in to impulse. Giving in to emotional sort of immediacy. And the part of the brain that’s most central to whether or not that happens is the frontal cortex. Most recently evolved part of the brain, we’ve got more of it proportionally or more complexly than any other primate species out there. It’s the part of the brain that does impulse control, long term planning, emotional regulation. It does all the stuff where it’s the frontal cortex that whispers in your ear saying, “Do you really really want to do that right now? If you do that you’re going to regret it. It seems like a great idea.” Frontal cortex about that.
Okay, so when we look at our moments of life where there’s that enormous temptation to do the impulsive thing and—what’s going to determine whether the world will be freed of impulsive horrors?“If only we could all get stronger frontal cortices trained in childhood to be able to hold out where you could have one marshmallow right now but if you wait you can get two later, and training from early age so that your frontal cortex has the most like fabulous aerobic metabolism ever, and it could just make you—“
And what the studies suggest is: at all sorts of junctures of doing the harder thing yes, having a really robust studly frontal cortex may do you a lot of good there.
But when you do sort of the truly difficult thing, when you see people who are the ones who run into the burning building to save the child and they leap into the river when everybody else is standing there like headless chickens—When you look at those people they’re not doing it because they’ve got the most amazing frontal cortexes on earth that could reason through the long-term consequences of “oh, what if nobody in society came to the aid of strangers?”
What they do is: they do it automatically.
You ask anybody who does one of these heroic acts what were you thinking when you jumped in the river. And the answer is always the same: “I wasn’t thinking. Before I knew it I had jumped in.”
When we do our most amazingly wondrous altruistic acts it’s not because we’ve got the most incredible frontal cortexes on earth that could like reason us. It’s because it’s out of the realm of the frontal cortex and it’s out of the realm of temptation and limbic stuff. We do the harder thing in a case like that because for us it’s not the harder thing. It’s become automatic, and that’s where you see it. You see the best success with temptation when it isn’t tempting, when it’s automatic, when we’ve distracted ourselves. All of that frontal like “work your way through the right decision” gets you only so far.
A fabulous study addressing this. This was work by a guy at Harvard named Josh Green who put people in a study in a brain scanner, of some task where if they got it right they get a reward afterward. So there’s an incentive to get it right. And this wonderful manipulative setup where at various points people were under the impression that there was a glitch in the system and the computer wasn’t registering their answers, so all they had to do was think what their answer was and then tell you afterward when they heard the correct answer had they had the right answer or not.
In other words they could cheat. And what you would see is it was a random task, so most of the time people were having about a 50 percent success rate and along comes the opportunities to cheat.
And if people’s accuracy suddenly jumps up at that point, aha, that’s how you detect a cheater or someone who’s lying at that point. So the question becomes what’s going on with brains of people who cheated at those opportunities and what you saw was as soon as that act came up their frontal cortexes activated like mad. They’re wrestling with Satan! They’re wondering if they should do it not! They’re wondering if they should have done it the last time when they were honest! They’re wondering if they’re ever going to – they’re wrestling all of that.
Okay, so that makes sense. Then you look at the people who cheating opportunity or otherwise never cheat. So what’s going on with them. And we’ve got the two models there. One of willpower: It’s because they’ve got frontal cortexes that can just like be stoic and Calvinist and gumption out the yazoo there.
Or is it a state of grace? They don’t cheat because you don’t cheat.
And the prediction there is if it’s all about willpower, as soon as the opportunity to cheat comes up their frontal cortices are going to go through the roof in terms of activity. If it’s a matter of grace, whatever.
And it was a matter of grace. The people who never cheated: it wasn’t because they had the strongest frontal cortexes. It’s because you don’t do that. It was that simple. It wasn’t a temptation. And that’s much more of a model of “it’s not a realm of just having to work so, so hard to feel for somebody else or not pocket that thing even though nobody’s looking. You just don’t do that.” It’s automatic.