Abstract

This study was carried out to investigate any tribal and sexual differences in the second to fourth digit ratio (2D:4D) of Igbos and Yorubas in Nigeria. Eight hundred and forty (840) Nigerian adolescents were used for the study. These comprised 210 Igbo males, 210 Igbo females, 210 Yoruba males and 210 Yoruba females. A digital venier caliper was used to measure the length of the second digit (2D) and fourth digit (4D). The ratio 2/4D was then calculated for each subject. Result from the study showed 2/4D was sexually dimorphic in the two tribes. Males demonstrated lower digit ratio (0.96 on the right hand of Igbos and Yorubas and 0.94 on the left hand of the two tribes) than females (0.97 on the right hand and 0.95 on the left hand). The differences observed between males and females in both tribes were significant (p<0.05). However, no significant difference was observed between the two groups (p>0.05). Thus, digit ratio amongst Yorubas and Igbos is sexually dimorphic and may not necessarily be affected by tribe and ethnicity.  It may be more related by lattitude as suggested by various researchers.

Key words: Digit ratio, Igbos and Yorubas.