[This is an] extremely simple question to ask... someone who's depressed: Ask them, 'Is there something you're doing or trying to do that seems so important you can't possibly give it up even though it's pretty clear you're never going to succeed?'

We now know there are a lot of genes that influence whether you get a mental illness or not, but they're almost all influencing things by 1% or less.

What other people think about us just matters enormously—to what friends we have, and what jobs we get, and who our lovers are, and everything ... I think we've been shaped by natural selection to do things that other people will appreciate.

I think all of us are designed so we're constantly preoccupied by our status, and by achieving things, and what we're not achieving, and by other people—I think this makes us miserable.

Natural selection, when it comes to sex and reproduction, gets us to do all kinds of stuff that's bad for our health and longevity but good for our genes.

People can do better at deceiving other people if they deceive themselves about their own impulses.

A big thing about emotions—a huge point—is that a lot of emotions [have] nothing to do with how you feel; it's only about what you do because the only point of emotions is to get you to do stuff differently.

There are three things you can change to help someone who's got an emotional problem: one is the situation itself, two is how you think about the situation, and three is the brain.