Gender Determination from Directional Asymmetry of Digit Lengths and Digit Ratios (2D: 4D) among Medical Students Belonging to Southern Parts of India

Directional asymmetry of digit ratios(D: r-l) is the difference between the ratio of index finger to ring finger (2D: 4D) of right hand and left hand. Directional asymmetry of digit ratios has been associated with masculine traits in men and women. Digit lengths of index and ring finger of males and females also show directional asymmetry. Whether directional asymmetry of digit ratios and digit lengths can help in gender determination in forensic settings has to be explored.

Digit lengths of index and ring finger and their ratio (2D: 4D) of both right and left hand of 54 male and 66 female medical students were taken with a digital vernier calipers and the significance of difference between digit lengths & 2D: 4D of right and left hand (directional asymmetry) among gender groups was observed using appropriate statistical methods.

This study replicated the findings of previous studies that there was significant difference between Right hand 2D: 4D of males and females (p<0.1), males having lower 2D: 4D. There was no such finding in left hand 2D: 4D. This study did not find any significant difference in directional asymmetry of digit ratios and digit lengths among gender groups in the study sample. Interestingly(though not statistically significant), left sided finger lengths (both index & ring) were more than right in males. Right sided finger lengths (both index & ring) were more than left in females.

There was no significant difference in directional asymmetry of 2D: 4D and 2D, 4D lengths among gender groups in the study sample. Males showed mild left sided asymmetry, females right sided asymmetry (statistically not significant).