Estimation of Sex From Index and Ring Finger Lengths in An Indigenous Population of Eastern India

Abstract

Introduction: Forensic anthropology involves the identification of human remains for medico-legal purposes. Estimation of sex is an essential element of medico-legal investigations when identification of unknown dismembered remains is involved. Aim: The present study was conducted with an aim to estimate sex from index and ring finger lengths of adult individuals belonging to an indigenous population of eastern India. Materials and Methods: A total of 500 unrelated adult individuals (18-60 years) from the Rajbanshi population (males: 250, females: 250) took part in the study. A total of 400 (males: 200, 200 female) participants were randomly used to develop sex estimation models using Binary Logistic Regression Analysis (BLR). A separate group of 200 adults (18-60 years) from the Karbi tribal population (males 100, females 100) were included to validate the results obtained on the Rajbanshi population. The univarate and bivariate models derived on the study group (n=400) were tested on hold-out sample of Rajbanshi participants (n=100) and the other test population of the Karbi (n=200) participants. Results: The results indicate that Index Finger Length (IFL) and Ring Finger Length (RFL) of both hands were significantly longer in males as compared to females. The ring finger was longer than the index finger in both sexes. The study successfully highlights the existence of sex differences in IFL and RFL (p<0.05). No sex differences were however, observed for the index and ring finger ratio. The predictive accuracy of IFL and RFL in sex estimation ranged between 70%-75% (in the hold out sample from the Rajbanshi population) and 60-66% (in the test sample from the Karbi population). A Receiver Operating Curve (ROC) analysis was performed to test the predictive accuracy after predicting the probability of IFL and RFL in sex estimation. The predicted probabilities using ROC analysis were observed to be higher on the left side and in multivariate analysis. Conclusion: The study concludes that sex estimation from index and ring finger lengths could be of utility when more reliable means of sex estimation are not available during medico-legal investigations.

Keywords

• forensic anthropology
• index finger length
• index-ring finger ratio
• ring finger length
• sex estimation
• rajbanshi