The Brain: The Story of You

by David Eagleman

When deciding whether or not to gobble down the ice cream, some networks in your brain want the sugar; other networks vote against it based on long-term considerations of vanity; other networks suggest that perhaps you could eat the ice cream if you promise yourself you’ll go to the gym tomorrow. Your brain is like a neural parliament, composed of rival political parties which fight it out to steer the ship of state. Sometimes you decide selfishly, sometimes generously, sometimes impulsively, and sometimes with the long-view in mind. We are complex creatures because we are composed of many drives, all of which want to be in control.

Across the animal kingdom, every creature is wired to seek reward. What is a reward? At its essence, it’s something that will move the body closer to its ideal set points. Water is a reward when your body is getting dehydrated; food is a reward when your energy stores are running down. Water and food are called primary rewards, which directly address biological needs.

In the case of humans, we can find even very abstract concepts rewarding, such as the feeling that we are valued by our local community. And unlike animals, we can often put these rewards ahead of biological needs. As Read Montague points out, “sharks don’t go on hunger strikes”: the rest of the animal kingdom only chases its basic needs, while only humans regularly override those needs in deference to abstract ideals. So when we’re faced with an array of possibilities, we integrate internal and external data to try to maximize reward, however it’s defined to us as individuals.

In all these cases, people structure things in the present so that their future selves can’t misbehave. By lashing ourselves to the mast we can get around the seduction of the now. It’s the trick that lets us behave in better alignment with the kind of person we would like to be. The key to the Ulysses contract is recognizing that we are different people in different contexts. To make better decisions, it’s important not only to know yourself but all of your selves.