Abstract
The aim of the study was to determine sexual dimorphism and to predict sex using thumbprint ridge density and thickness among the Hausa ethnic group of Nigeria. A total of 283 subjects comprising 147 males and 136 females participated in the study. The density was determined from the count of ridges found diagonally within 25 mm
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using an indirect method of ridge thickness measurement. The results showed that the ulnar ridge density of males (10.01 ± 1.31) was significantly (p < 0.05) lower than that of females (10.91 ± 1.69) in the right thumb. The ridge thickness was observed to have an inverse relation with ridge density. It was also noted that the right ulnar ridge count was the single best variable to predict sex (63.4% accuracy). For the left thumbprints, the proximal ridge thickness predicted the sex (62.8% accuracy). The predicted probabilities of binary logistic regression showed that ulnar ridge count and proximal ridge thickness were the best predictors with a higher area under the curve (>0.5) in the right and left thumbprints respectively. In conclusion, different regions of thumbprints have different potentials in term of sex prediction. Ridge density and thickness hold potential as tools for sex inference among the Hausa population of Nigeria.