A preliminary study on sex differentiation in thumbprint sweat pore characteristics in the Indian population

Fingerprint analysis is one of the pillars of forensic science and a tool used in personal identification. The importance of fingerprints lies in their uniqueness, permanence, and classifiability. The examination of fingerprints can be done at three levels. The first level focuses on macro features like pattern type, orientation, and core. The second level includes ridge characteristics like minutiae. Individualization is possible at this level. The third level deals with micro-characteristics such as sweat pores, incipient ridges, and edge contours. The aim of this study is to study sweat pore morphology and its potential for sexual dimorphism in Indian adults. The study uses quantitative comparative methodology. It included 100 Indian students, with an equal male-to-female ratio, aged 18 to 25 years. The collected right-hand thumbprint was analyzed using a stereozoom microscope and Vi-Plus software. Three sweat pore parameters, pore density, inter-pore distance, and inter-pore angle, were used in this study. The findings showed statistically significant differences between male and female fingerprints for all three sweat pore parameters (p < 0.05). Sweat pore density was found to be significantly higher in females, whereas pore-to-pore distance and pore-to-pore angle were higher in males. Effect size analysis showed a large difference for pore density (Cohen's d = 1.95) and inter-pore distance (rank-biserial correlation = 0.94), and a moderate effect for inter-pore angle (Cohen's d = 0.57). A significant negative correlation was observed between pore density and inter-pore distance in both groups. Binary logistic regression and ROC analysis revealed high classification performance, with an AUC of 0.972, an accuracy of 93%, a sensitivity of 94%, and a specificity of 92%. These results highlight sexual dimorphism in sweat pore parameters and their potential to be used as a supportive feature in forensic sex differentiation. However, further validation is required with a larger, more diverse population.