When you look at the brain regions associated with picking up data from the body, a huge amount of the brain is devoted to picking up information from the lips and tongue.

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.

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

There's magic to love... Millions of years ago we evolved three basic drives: the sex love, romantic love, and attachment to a long-term partner. These circuits are deeply embedded in the human brian. They're going to survive as long as our species survive on what Shakespeare called, this "mortal coil."

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

Why do we feel jealousy? Therapists often regard the demon as a scar of childhood trauma or a symptom of a psychological problem. And it's true that people who feel inadequate, insecure, or overly dependent tend to be more jealous than others.

Research shows that couples who have a lot of similarities, including intellectual compatibility, end up staying together.