Role of 2nd Digit:4th Digit Ratio(2D:4D Ratio) in Establishing the Biological Profile of an Individual

Abstract

Introduction: The process of identification focuses mainly on establishing the biological profile by
estimating the sex, age and stature which significantly narrows down pool of suspects. The 2D:4D ratio
is a sexually dimorphic trait which is influenced by prenatal estrogen and testosterone levels. Studies also
suggest that there might be strong relationship of this ratio and stature and age well. This study is taken in
combination of all the 3 primary parameters of biological profile and co-related with that of 2D:4D ratio.
And there is no such study conducted in this part of Karnataka.
Aims and Objectives: To study the role of 2D;4D ratio in establishing the biological profile(Sex, Age and
stature) of an individual by manual digital measurements and digital print measurements.
Material and Method: Hundred first year medical students (n=100) (males= 50 and females =50) of S.
N. Medical college, Bagalkot were included in the study. Authentic proof of age was collected and height
measured by stadiometer and 2d:4d by digital callipers for both hands. SPSS 17.0 used to analyse the data.
Results: In Males, the ratio varied from 0.89 to 1.04 with mean and standard deviation of 0.97 ± 0.03 on
right side and on left side it varied from 0.85 to 1.03 with mean ± SD of 0.98 ±0.04. While in females ratio
varied from 0.91 to 1.11 with Mean ± SD of 0.97±0.04 on right side and on left side it varied from 0.83 to
1.12 and Mean ± SD of 0.98 ±0.04 on left side
Based on the mean 2D:4D ratio for both the sexes, 0.97 on right and 0.97 on left side, sectioning point was
derived. When all the cases below and equal to 0.97 were considered as males and those above 0.97 were
considered as females, one could accurately determine the sex up to 90% accuracy.
Conclusions: 2D:4D ratio can be effectively and accurately used to establish the biological profile of an
individual which can help forensic experts and medicolegal experts to narrow down the pool of suspects
in crime or identify the victims of crime, mass disasters, road traffic accidents etc. Moreover 2D:4D, ratio
relatively less time consuming, and cost effective.