I don’t think we’re an animal that was built to be happy; we are an animal that was built to reproduce.

You know, when you've been dumped, the one thing you love to do is just forget about this human being, and then go on with your life - but no, you just love them harder.

Both sexes like the exercise and challenge of sports, but for men it's also a basic display behavior for impressing and winning a mate.

If two very different people pool their DNA, they'll create more genetic variety, and their young will come to the job of parenting with a wider array of skills.

Romantic love is an addiction: a perfectly wonderful addiction when it's going well, and a perfectly horrible addiction when it's going poorly.

You can really get poked in the back and not feel it very much, but just a feather around your lips and you really do feel it.

You fall in love with somebody who fits within what I call your 'love map,' an unconscious list of traits that you build in childhood as you grow up. And I also think that you gravitate to certain people, actually, with somewhat complementary brain systems.