I think romantic love evolved to enable you to focus your mating energy on just one individual at a time, thereby conserving mating time and energy.

More and more of us live segmented, compartmentalized lives. This isn't natural. For millions of years, our forebears knew everyone around them and everyone knew them.

In that early-love stage, you're in that state of exhilaration. You talk till dawn. You become obsessed with 'What does he think?' 'Does he like me?' 'Does he think I'm fat?'

When you fight, anger drives up testosterone in both men and women.

After a man falls madly in love, he no longer cares how old she is.

Men want to think women don't cheat, and women want men to think they don't cheat, and therefore the sexes have been playing a little psychological game with each other.

Women are naturally prone to compete over their mates.

As women in industrial societies join the paid workforce, they gain the economic means to depart unhappy marriages more easily.

Women are better at reading body language everywhere in the world. As a matter of fact, it's associated with the female hormone estrogen. Women are better at figuring out of tone of voice, reading your face and posture and gesture.

A woman will toss her head and a man will say, 'Oh she's trying to pick me up,' when in fact she's not doing that at all. So, women actually have to be a little careful with what they do, because men will pick up things that they didn't mean.

When people tell you to walk a certain way, it's like not thinking of a purple tomato. You can't not do it.

In America, we are demanding everything from our marriage.

Since when is anyone truly honest with anyone?

Office romances are few, short, and not usually destructive.

A lot of people head into courtship looking for fireworks. Don't pass up a chance by dumping someone after a first date because you don't feel the fireworks. The fireworks can happen at any time and be maintained.

When you're in the throes of this romantic love, it's overwhelming - you're out of control, you're irrational, you're going to the gym at 6 A.M. every day - Why? Because she's there.

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.

There were real reasons that you were attracted to somebody originally. The brain doesn't pick willy-nilly. Unless you part ways hating each other for some reason, that mechanism could get triggered again. You can literally fall in love again.

Liberals and conservatives are looking for entirely different things. Their attitudes toward romance and how they court are really dramatically different. There's almost no overlap.

I can't conceive of caring more about my president than my own partner.

There's every reason to think SSRIs blunt your ability to fall and stay in love.

There are cognitive processes and limbic reactions associated with basic emotions. And you can change brain chemistry, but you're still not going to change memories and experiences in a human being.

Romantic love allows you to focus mating energy. Attachment sustains that relationship as long as necessary to raise your baby.

Of all the foods we share, there is nothing more primordial than meat. It's no surprise that meat-eaters still want a partner who will give, receive and share this primordial symbol of a budding partnership.

The women's movement is just a symptom of basic changes in the economy that are favoring women.

I've always maintained that men were more romantic than women.

The Internet lets women use words, which is their natural tool. Little girls speak in more complex, grammatical sentences than little boys do, and women never lose that superiority in verbal ability.

Men tend to be hierarchical, but women are driven to make lateral connections so they can cooperate.

We all have restlessness in long-term relationships.

You can get into a very fancy car and know everything about the engine, but when you drive in that car, you feel that rush. In the same way, I think the more you know about love, the more you can enjoy it. And knowing about your personality type, who you are and what kind of person you're dealing with gives you a great leg up.

We still have community, but we don't seem to have local community. Even in a small town where you know your neighbors and your mother's down the street, they're not in arm's length.

Like most animals, we're wired to associate height with power.

In courtship, who wins and who loses will determine who passes on their DNA to tomorrow.

A woman of 40 or 50 or 60 can take estrogen replacements, get facelifts, spend her money in bars.

We're apt to fall in love with those who are mysterious and challenging to us.

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.

When you can't have someone but you're not willing to accept that, you try harder and become more extreme about it. Either you win the person back or you drive him away.

Women have a better sense of smell than men do, and it's even sharper in the middle of their menstrual cycle, when estrogen levels peak and women are more likely to be deciding whether a man's attractive.

Women like signs of money and education - things that indicate that not only is this guy going to have some resources, but he's also willing to share them.

Touch is the mother of the senses. Not only are women more sensitive when they touch, but they're also more sensitive to being touched.

Women spend their lives trying to look good for men. So a woman who feels she's sending the right visual signals is pleased with herself.

Almost always, when I'm on TV, the producers who call me, who negotiate what we're going to say, is a woman.

I think the happiness we find, we make.

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.

People have often asked me whether what I know about love has spoiled it for me. And I just simply say, 'Hardly.' You can know every single ingredient in a piece of chocolate cake, and then when you sit down and eat that cake, you can still feel that joy.

From my studies of genetics and neuroscience I have come to believe that people fall into four broad personality types - each influenced by a different brain chemical: I call them the Explorer, Builder, Director, and Negotiator.

We are wired to find love.

Women, it turns out, are built to lead - particularly in the modern world.

You size up someone physically in less than one second - too tall, too short, too fat, too thin, too old, too young, too stuffy, too scruffy.

Women are very attracted to a low voice because it's linked to testosterone, which for millions of years was a sign that men had very good spacial skills and would have been very good at hunting and finding their way back home.