Social scientists who study the family have long been interested in the question "Who marries whom?" On one level, the study of mate selection is conducted from the perspective of family as a social institution. Emphasis is placed on the...

Assortative mating (also called assortative pairing) takes place when sexually reproducing organisms tend to mate with individuals that are like themselves in some respect (positive assortative mating) or dissimilar (negative assortative mating). In...

Why are so many people fat? Scientists have come up with some novel excuses, including air conditioning, lack of sleep, fewer smokers, and more sex among obese people, which can produce chubby kids. Twinkies aren't the only things weighing America...