Digit ratio

Finger length ratio refers to the ratio of the length of the index finger to the length of the ring finger and is therefore 2D: 4D ( D digitus, the Latin word for finger / toe) called. The finger length ratio correlated with the ratio of fetal estradiol on fetal testosterone levels. Correlative studies show a relationship between the finger length ratio and fetal growth, handedness, autism, Asperger's syndrome, sperm counts, family size, age at heart attack in men and breast cancer in women. Furthermore, it was shown that alcohol dependence and dependent video games with smaller 2D: 4D finger length ratio are associated.