A new research states the length of the fourth finger influences the quantity of sex hormones. The number four is related to the receiver of the sex hormones, reveals Dr. Cohn and Dr. Zengui Zheng from the University of California.

The research reveals that the size of the fourth finger in men is bigger in size than the index finger, whereas the rule is opposite among women. The sequence is formed before the development of the bones of the infant as a male and female.

The researchers commenced a study on mice and found that increased level of testosterones influenced the size of the 4th digits in the paws of the newborn mice, on the other hand mice with high level of oestrogen were liable to possess feminine looks than the male ones.

The study of the genes among male and females have found the relation between the finger sizes that is influenced from the quantity of sperms. As per Dr. Cohn, “Sex hormones affect finger length, and the ratio is fixed before the bone has even developed. This happens during a narrow window of development but it stays fixed throughout life”.