Preliminary study on morphometric analysis of the human scalp hair for discrimination of ethnic Malay and ethnic Chinese in Malaysia

Abstract

Background: Hair is one of the most frequently encountered trace evidence in crime scenes. It has been used for differentiating races or identifying species of animals. An understanding of intra- and inter-variation of human scalp hair may enable discrimination based on ethnicity. This study aims to discriminate the ethnic Malays and ethnic Chinese in Malaysia based on three morphometric measurements of the human scalp hair. Method: The sample group was composed of 100 Malaysians, 50 each (i.e. 25 males and 25 females) from ethnic Malays and ethnic Chinese. Each subject has provided 20 strands of hair. The hair width (HW), scale layer difference (SLD), and medullary index (MI) of each hair were determined using a compound microscope. Following that, the inter-variation of hair was evaluated according to (a) head regions, (b) sex, and (c) ethnic groups and assessed using descriptive and inferential statistics, i.e. independent t test and Wilcoxon’s rank-sum test. Results: Results show that Malays and Chinese are different in all the three morphometries. However, Malay males are different from females only in terms of SLD, and Chinese males and females could be discriminated using MI. Next, hair originating from upper and lower head regions, regardless of ethnicity and sex, are not significantly different. Conclusion: In conclusion, Malays and Chinese could be discriminated based on morphometric measurements of scalp hair. The finding sheds new light on the feasibility of differentiating ethnic groups using physical measurements alone.