|>>|| No. 21257
>While the subjects watched on a computer screen, Chivers, who favors high boots and fashionable rectangular glasses, measured their arousal in two ways, objectively and subjectively. The participants sat in a brown leatherette La-Z-Boy chair in her small lab at the Center for Addiction and Mental Health, a prestigious psychiatric teaching hospital affiliated with the University of Toronto, where Chivers was a postdoctoral fellow and where I first talked with her about her research a few years ago. The genitals of the volunteers were connected to plethysmographs — for the men, an apparatus that fits over the penis and gauges its swelling; for the women, a little plastic probe that sits in the vagina and, by bouncing light off the vaginal walls, measures genital blood flow. An engorgement of blood spurs a lubricating process called vaginal transudation: the seeping of moisture through the walls. The participants were also given a keypad so that they could rate how aroused they felt.
>The men, on average, responded genitally in what Chivers terms “category specific” ways. Males who identified themselves as straight swelled while gazing at heterosexual or lesbian sex and while watching the masturbating and exercising women. They were mostly unmoved when the screen displayed only men. Gay males were aroused in the opposite categorical pattern. Any expectation that the animal sex would speak to something primitive within the men seemed to be mistaken; neither straights nor gays were stirred by the bonobos. And for the male participants, the subjective ratings on the keypad matched the readings of the plethysmograph. The men’s minds and genitals were in agreement.
>All was different with the women. No matter what their self-proclaimed sexual orientation, they showed, on the whole, strong and swift genital arousal when the screen offered men with men, women with women and women with men. They responded objectively much more to the exercising woman than to the strolling man, and their blood flow rose quickly — and markedly, though to a lesser degree than during all the human scenes except the footage of the ambling, strapping man — as they watched the apes. And with the women, especially the straight women, mind and genitals seemed scarcely to belong to the same person. The readings from the plethysmograph and the keypad weren’t in much accord. During shots of lesbian coupling, heterosexual women reported less excitement than their vaginas indicated; watching gay men, they reported a great deal less; and viewing heterosexual intercourse, they reported much more. Among the lesbian volunteers, the two readings converged when women appeared on the screen. But when the films featured only men, the lesbians reported less engagement than the plethysmograph recorded. Whether straight or gay, the women claimed almost no arousal whatsoever while staring at the bonobos.