Contra Scott on Fake Bisexuality

My time has come!

[Content note: brief mention of rape, zoophilia]

I agree with Scott Alexander entirely that you should stop accusing people of faking bisexuality. Unfortunately, the research he cites to show that women are very likely to be bisexual is crap. I’m not casting shade against Scott Alexander here—we all accidentally cite bad research sometimes, and the way that this is bad is a little subtle.

Both women and men get erect in sexual situations, although men’s erections are easier to see.¹ Typically, female genital arousal is measured using the vaginal plethysmograph, which measures blood flow to the vagina (that is, the erection of the internal clitoris). Male genital arousal is measured using any number of devices that measure the strength of an erection.

Over the past forty years, it’s a very well-replicated pattern that male genital arousal tends to be orientation-specific: that is, gay men get erections about men and straight men get erections about women. However, the same studies show that female genital arousal is not orientation-specific: regardless of their orientation, women are genitally aroused by both men and women. However, the more sexually explicit the stimuli, the more genitally aroused women are.

Genital arousal is also surprisingly poorly correlated with subjective sexual arousal. Genital arousal explains about 44% of the variance in subjective sexual arousal for men. That’s a pretty high level of agreement, but with the exceptions that are familiar to anyone who has been or has had sex with a man: the inappropriate erection during math class, the great sex where the guy just can’t get it up. A lot of genital arousal/subjective arousal disagreement will pass unnoticed: how many people can distinguish “40% of the way to fully hard” and “50% of the way to fully hard”?

Conversely, genital arousal explains only seven percent of the variance in subjective sexual arousal for women. They’re basically uncorrelated.