Researchers find out how a newlywed's brain works.

On Valentine's Day, we asked the experts how biology and psychology affect love, relationships and sex.

Valentine's Day comes just once a year, but love is in the air year-round on our campuses. Research on the psychological and physical aspects of l'amour is no mere flirtation.

Take the work of UC Berkeley's Greater Good Science Center. Unlike Paul Simon (who lyrically detailed 50 ways to leave one's lover), they offer five ways to renew old romance. Gratitude — one of the center's core subjects — also fuels long-term relationships.