From The New York Times:
Take the question of promiscuity. Everyone has always assumed — and early research had shown — that women desired fewer sexual partners over a lifetime than men. But in 2003, two behavioral psychologists, Michele G. Alexander and Terri D. Fisher, published the results of a study that used a “bogus pipeline” — a fake lie detector. When asked about actual sexual partners, rather than just theoretical desires, the participants who were not attached to the fake lie detector displayed typical gender differences. Men reported having had more sexual partners than women. But when participants believed that lies about their sexual history would be revealed by the fake lie detector, gender differences in reported sexual partners vanished. In fact, women reported slightly more sexual partners (a mean of 4.4) than did men (a mean of 4.0).
So how sketchy is the research on human sexual behavior, anyway?
Nearly every kind of BDSM play under the sun, and talking dirty. Most people can't orgasm from those alone.
Wait... People count that as sex? I knew phrases like “cyber sex”, “phone sex”, etc., but I thought people thought of them as cases where [adjective] [noun]s are not actually [noun]s, as with “dwarf planet”, “fake money”, “soy meat”, etc., and I'm surprised if there are people who would count that as sex when asked how many people they've had sex with (except possibly as self-sophistry in attempt to fool the lie detector).