>"Odors, for instance, are strongly linked to emotions, memory, and sexual behavior. Women’s noses and brain circuits are particularly sensitive just before ovulation—not just to ordinary scents but also to the imperceptible effects of male pheromones. Pheromones are social chemicals that humans and other animals release into the air from their skin and sweat glands. They are found in male body sweat. Pheromones alter brain perceptions and emotions and influence desires—such as desire for sex. The brain changes its odor sensitivity as the estrogen surge leads up to ovulation"
>"Using the body odor of men and the noses of women, Jan Havlicek of Charles University in Prague has hatched a controversial theory about pheromones and the female brain. He found that ovulating women who already have partners preferred the smell of other more dominant men but that single women showed no such preference. Havlicek argues that his findings support the theory that single women want nurturing men who will help raise a family. But once the home is secured, they have the biological urge to sneak around with men who have the best genes."
>"Yet another blow to the myth of female fidelity is the dirty little secret in human genetic studies—up to 10 percent of the supposed fathers researchers have tested are not genetically related to the children these men feel certain they fathered. Ethical constraints prevent scientists from revealing this detail to anyone."
>"Another study found that women who have lovers on the side start to fake orgasm more often with their stable partners. Faking orgasm with their steady partners was more common even among women who reported only flirting with other men. Men are biologically geared to look for cues of sexual satisfaction for a reason—such satisfaction is reassurance about women’s fidelity. [...] these findings suggest that female orgasm is less about bonding with only the nice guys you want to marry than about a shrewd, subconscious, primitive evaluation of outside lovers’ genetic endowment."