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

What our grandmothers told us about playing hard to get is true. The whole point of the game is to impress and capture. It's not about honesty. Many men and women, when they're playing the courtship game, deceive so they can win. Novelty, excitement and danger drive up dopamine in the brain. And both sexes brag.

Today, most women are surrounded by ingenious gadgets. They don't grow the peas or raise the chicken that they serve for dinner; instead they hunt and gather in the grocery store. They go through catalogs or department stores to buy clothes instead of shearing sheep, carding wool, and weaving cloth for skirts and coats and blankets.

A lot of people have been romantically in love with somebody who they feel wasn't appropriate to marry.

Despite the myth that men are less committed, they are predisposed to desire marriage.

Kissing is not just kissing. It is a major escalation or de-escalation point in a powerful process of mate choice.

Neither gender is routinely more jealous - although women are more willing to work to win back a lover, while men tend to flaunt their money and status and are more likely to walk out to protect their self-esteem or save face.