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

Any time you choose not to hide your tattoo, you're limiting your social sphere, because they're not popular in big business.

In general, men are wired to notice obvious signs that convey interest in mating - a warm smile, for example - and ignore other subtleties, like if your lipstick is faded.

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

Women are naturally prone to compete over their mates.

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

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.