The sexual patterns of couples also indicate that women are sexually adaptable. The female libido fluctuates throughout the month, based on ovulation and the menstrual cycle. But couples do not appear to have sex more or less frequently based on what time of the month it is. Rather, couples have sex in weekly and daily patterns–in the evenings and/or on weekends. A 1991 survey looked at how the gap between how frequently men and women desire sex and how often they actually have sex; the gap is bigger for women, 82 percent of whom had sex when they did not desire it, compared to 60 percent of men.

What could explain this flexibility? Baumeister proposed that “Women might be more willing to adapt their sexuality to local norms and contexts and different situations, because they aren’t quite so driven by strong urges and cravings as men are.”…

So Baumeister and two (female) colleagues set to work reviewing hundreds of studies about human sexuality and found consistently that women are less motivated by sex than men are.

For men, they found, the goal of sex is sex itself. One 1996 study found that seven in ten men–compared to four in ten women–said the goal of sexual desire was simply having sex. In the same study, 35 percent of women said that love and intimacy were important goals of sex compared to 13 percent of men. Men also think about sex more, according to studies. When men and women monitor their sexual urges over a seven-day period, men report having twice as many sexual urges as women do.