Repeated studies have been confirming Digit Ratio Theory, the idea that one’s personality is reflected in the comparative lengths of his or her fingers. One thing the fingers can tell you? Sexual orientation.

The theory’s basis is that greater prenatal exposure to androgens (including testosterone) decreases the 2D:4D ratio, or index finger length : ring finger length. Greater exposure to oestrogen, of which androgens are precursors, increases the ratio.

Accordingly, most men have ring fingers longer than their index fingers, and most women have index fingers longer than or about the same size as their ring fingers. The differences are usually more noticeable on the right hand.

Studies have found that those with fingers of comparably similar lengths (even more similar for women) are more likely to be homosexual, approximating the “crossover” point. Furthermore, self-identified “butch” lesbians have an almost 1:1 ratio compared with self-identified “femme” lesbians.

Men with longer ring fingers tend to be more fertile, aggressive, run faster, and lack verbal skills; women with longer index fingers tend to be more fertile, unassertive, neurotic, and likely to avoid risks.