MICROSCOPIC SEX-BASED DIFFERENTIATION OF HUMAN SCALP HAIR AMONG UNIVERSITY STUDENTS IN NIGERIA

Abstract

Scalp hair is one of the most resilient biological materials frequently encountered in forensic investigations, offering valuable trace evidence, especially when nuclear DNA is degraded or absent. This study examined sex-based differences in microscopic characteristics of scalp hair among a Nigerian population, aiming to provide population-specific forensic reference data. A total of 400 hair samples, comprised of 200 samples each from males and females, were collected from healthy adults aged 18 to 30 years old. Using stereomicroscopy, each sample was assessed for hair shaft diameter, medullary diameter, hair length, density, follicular size, texture, pigmentation, and cuticular integrity. Statistical analysis was performed using t-tests and ANOVA at a significance level of p < 0.05. The results showed that male hair had significantly larger shaft and medullary diameters and follicle size, while female hair had higher density and longer average length. Differences in hair texture were also observed, with a greater proportion of curly and wavy hair among females. Pigmentation remained consistent in male samples but showed distal fading in females. Cuticle preservation was generally better in males, whereas partial or complete cuticle loss was common in female samples. These findings reveal clear, measurable differences in scalp hair morphology between sexes and underscore the forensic value of microscopic hair analysis. Moreover, the study contributes crucial localized data for forensic investigations in the African context.