13 Things Every Woman Doesn't Know About Her Own Body

You're biologically built to weep.

Adult women cry 5.3 times a month; adult men, about 1.4 times, according to William H. Frey II, PhD, a neuroscientist and author of Crying: The Mystery of Tears. Some may assume that this is just because society is more comfortable with a weepy woman than a melting-down man, but Frey says that there are several biological factors that make women more likely to shed tears. At the cellular level, women's tear glands are anatomically different from men's, says Frey (some studies say they're bigger), and that's one of the reasons we cry so easily. He adds that the hormone prolactin, well known for its role in lactation, also regulates the development of the tear glands and aids in the production of tears. Per Frey, by the time women are 18, they have 50 to 60 percent higher levels of prolactin in their bloodstream than men do. Great: That's just in time for the frustrations of adulthood.