Articulatory Loop

A couple years ago, a really fascinating study found that gay men and lesbians had lower index finger to ring finger length (2D:4D) ratios than their heterosexual counterparts, suggesting exposure to elevated levels of testosterone in utero for the homos. This result is fascinating, even though the study has not, to my knowledge, been replicated or further elucidated, and is thus to be taken with a healthy grain of salt.

Fast forward to today, when scientists have found that a lower 2D:4D ratio (and thus higher androgen exposure) correlates to more aggressive behavior. This doesn't fit with stereotypes of gay men, but does with stereotypes of lesbians. It is interesting to note that gestational testosterone levels do tend to increase down the birth order (higher for younger siblings), as do homosexuality and some forms of personality disorder. Hmmmm......

Both of these studies demonstrate rather nicely one of my favorite things about research: creative data gathering techniques. It's hard impossible to know directly how much testosterone was present in a person's mother's womb, but by finding a permanent physical train (finger length ratio) affected/determined by that amount, you can retrospectively infer the amount. So cool!