There was research proof that the ratio regarding the period of the next and 4th digits (index little finger and ring hand) is significantly adversely associated with testosterone that is prenatal favorably to oestrogen.
Studies calculating the hands discovered a statistically significant skew in the 2D:4D ratio (long band little finger) towards homosexuality with a much reduced ratio in bisexuals. It is strongly recommended that experience of high testosterone that is prenatal low prenatal oestrogen concentrations is just one reason behind homosexuality whereas experience of quite high testosterone amounts could be connected with bisexuality. This view offers an alternative to the suggestion that male homosexuality is genetic because testosterone in genereal is important for sexual differentiation. 13