What the length of your index finger says about you

The idea that the shape of your hands indicates something profound about your sexual proclivities, the films you like, your athletic ability and your prowess on the stock market seems bizarre.

And yet for many decades now, scientists have noticed an extraordinary link between the ratio of two digits on the hand — the ring and index fingers, known in scientists’ jargon as 2D and 4D — and a whole host of seemingly unrelated traits. Evidence is growing that this ‘digit ratio’, especially when applied to the right hand, is a fundamental indicator of sexuality, aggression and ­diseases suffered by men.