Why do women who have anal sex get more orgasms?

William Saletan in Slate:

Last week, I tried to figure out why more women are having anal sex and why it correlates so highly with orgasms. Since 1992, the percentage of women aged 20-24 who say they've tried anal sex has doubled to 40 percent. The percentage of women aged 20-39 who say they've done it in the past year has doubled to more than 20 percent. And 94 percent of women who received anal sex in their last encounter said they reached orgasm—a higher rate of orgasm than was reported by women who had vaginal intercourse or received oral sex.

Why? For obvious reasons—anatomical, evolutionary, and aesthetic—anal sex should, on average, be less attractive and satisfying than vaginal or oral sex. In last week's column, based on new survey data, I inferred that female orgasms caused anal sex rather than the other way around. The other acts reported by women who engaged in anal sex—vaginal intercourse, cunnilingus, partnered masturbation—delivered the orgasms. In turn, these women indulged their male partners' requests for anal sex.

Well, shame on me. Not for talking about sodomy—that taboo seems to be fading fast—but for doubting that women love it. These women are now coming forward to affirm that they're into it for their own pleasure, thank you very much.

More here.