THE CLAIM -- Babies tend to look like their fathers.

THE FACTS -- It's one of the first questions to cross a new parent's mind. Does the baby look like me? Studies suggest that, for fathers, the answer is usually yes.

In 1995, a study in Nature put the question to the test by having 122 people try to match pictures of children they didn't know -- at one year, 10 years and 20 years-- with photos of their mothers and fathers.

The group members correctly paired about half of the infants with their fathers, but their success rate was much lower matching infants and mothers. And matching the 20-year-olds with either parent proved to be just as hard.

The authors offered an evolutionary explanation for their findings: the phenomenon is a natural paternity test.