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

People live for love. They kill for love. They die for love. They have songs, poems, novels, sculptures, paintings, myths, legends. It's one of the most powerful brain systems on Earth for both great joy and great sorrow.

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

Whether you're married or not, relationships - and the satisfaction tied to them - are extremely important for increasing men's and women's quality of life.

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

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.

It's in our genes, we were built to wander.