VARIATION IN THUMBPRINT PATTERNS AND RIDGE DENSITY COUNTS BETWEEN TWO MAJOR ETHNIC GROUPS IN NIGERIA

The uniqueness of fingerprints makes it a valued biometric trait and since the prints are regularly seen
physical evidence in many crime scenes, forensic investigators employ them for sexual and ethnic
differentiations when solving criminal cases. This study was an attempt to discriminate sex and ethnicity
using thumbprint patterns and ridge density counts between Igbo and Efik tribes of Nigeria. The sample size
for this study includes 173 adults (Efik = 37 males, 44 females) and (Igbos = 61 males, 31 females),
randomly selected between the ages of 18-40 years. The subjects were asked to wash and dry their hands to
remove dirt and grease. The fingers (thumbs) of both hands were smeared with indelible ink and pressed in a
white plane paper. Using meter rule, 25mm each was measured from radial border, ulnar border, and
inferior quadrants respectively for fingerprint ridge density count. This data was analyzed using SPSS
Software version 21 Chicago Incorporated. The results of this study showed that both the males and females
of Igbo origin have predominantly loop fingerprint pattern, at the male to female ratio of 43% and 55%
respectively. In the contrary, the male and female of Efik ethnic group recorded more whorl print pattern at
the ratio of 54% and 50% respectively. More so, this results recorded sexual dimorphism (P<0.05) in the
various ridge density count across the two ethnic groups, even the ethnic comparison of both males to males
and females to females, recorded statistical significant difference (P<0.05) between the Igbos and Efiks.
Hence, the Igbos, irrespective of sex showed more loop fingerprint pattern, contrary to the whorl fingerprint
pattern more frequent amongst the Efiks.Thus, the present results will be of immense relevance in forensic
practice by unveiling the peculiarities of finger ridge density associated with gender and ethnic origin.