An explosion of research into female sexuality supports the notion that sexual orientation in women is different from that in men. Men seem to be more categorical in their sexual orientation; they are more likely to be either heterosexual or homosexual. Women, on the other hand, tend to be more flexible in their sexual orientation, less categorically heterosexual or homosexual. This is supported by studies using the Kinsey scale, in which women are more likely than men to fall in the middle of the scale, while men are more likely to fall on either end.

Fascinating new studies of the physiological response of men and women to various sexual images adds support to this theory. Meredith Chivers, Michael Seto, and Ray Blanchard measured genital response to different sexual images. While physiological response in men was, for the most part, oriented toward either adult women or men, women responded sexually to a much broader range of images. In fact, women had a (small) physiological response to images of bonobo chimps mating. Moreover, the physical response in women was often at odds with their verbal descriptions. In other words, what women said they responded to did not always correspond to their actual physiological arousal.

These findings are consistent with the distinction mentioned earlier between the physiological responses in women and their conscious emotional experience. These findings also align with Baumeister’s theory that sexuality in men tends to be relatively fixed and unvarying while sexuality in women is more fluid and more responsive to situational factors.