… Meanwhile, S. Marc Breedlove, a professor of neuroscience at Michigan State University, has become a giant of finger research. In 2000, his study, Finger-length Ratios and Sexual Orientation, appeared in the journal Nature. It features a handy graph. The reader can see that, on average, gay and straight women have distinctly different finger ratios – and gay and straight men have differing ratios, too. These distinctions, curiously, are true of the right hand or of the left, but not of both.
Breedlove made a more specific discovery two years later. He and several colleagues published a study called Differences in Finger-length Ratios Between Self-identified “Butch” and “Femme” Lesbians. Their findings are summed up in this sentence: “We surveyed individuals from a gay pride street fair and found that lesbians who identified themselves as ‘butch’ had a significantly smaller 2D:4D than did those who identified themselves as ‘femme'” …
So says a passage in the middle of this week’s Improbable Research column in The Guardian.