What do women want and why is their objective response of arousal so much different than their subjective response?

There was a fascinating article in the New York Times titled What do women want? In it Meredith Chivers did a study of a cross section of men and women and measured their response to a variety of stimuli that included homosexuality, heterosexuality and Bonobo Chimps having sex. The genitals of the volunteers were connected to plethysmographs. They were measured both objectively in this fashion and subjectively by their responses. The response by the men was typical of their stated preferences and their physical response was in keeping with their preferences.
The surprise was in the women who exhibited marked contrasts between their subjective and objective response of desire as measured by the plethysmograph. Their responses were all over the map. The readings from the plethysmograph(objective) and the keypad(subjective) weren’t in much accord. Many hypotheses have been formed by this study. One is that women had to be ready for sex in a variety of circumstances whether they welcomed in or not-i.e. rape. So therefore it would be less damaging to her body if she in fact was genitally aroused. And that response could be in marked contrast to her actual experience of desire.
Another is that a women’s ideas about the experience and enjoyment of sex are a veritable mish mash of emotions and societal standards which can create this incongruity.
AsSigmund Freud posed to one of his female disciples almost a century ago: “The great question that has never been answered and which I have not yet been able to answer, despite my 30 years of research into the feminine soul, is, What does a woman want?”