The ratio of the length of the index finger and the ring finger in males may be predictive of a variety of disorders related to disturbed hormonal balance, shows a study.
For the study, 103 male patients diagnosed with schizophrenia and 100 matched healthy male individuals were investigated.
The 2D:4D ratio may be an effective predictor of schizophrenia, found the team.
"Asymmetry index showed moderate discriminatory power and, therefore asymmetry index has a potential utility as a diagnostic test in determining the presence of schizophrenia," said Taner Oznur, co-author of the study that appeared in the journal Clinical Anatomy.
When the index finger is shorter than the ring finger, this results in a small 2D:4D ratio, showing a high exposure to testosterone in the uterus - there were significant differences between schizophrenia and control groups concerning the ratio of the lengths of the second digit to the fourth digit, as well as its asymmetry, in both hands.
