Helen Fisher

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.

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.

Hair that looks like it's been naturally sun-bleached makes you seem youthful, like you spend a lot of time outdoors. And that appeals to most people.

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.

Natural beauty really entices men. They will tell you this time and time again, and studies consistently prove it.

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.

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.

Along with our many human propensities, we evolved a huge cerebral cortex with which we make decisions.

The human brain is built to compare; it's Darwinian to consider an alternative when one presents itself.

There exists no culture in which adultery is unknown, no cultural device or code that extinguishes philandering.

You don't come home from the office to spend time with another job. Hopefully you come home to someone you can have a good time with.

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.