Unique Hair Properties that Emerge from Combinations of Multiple Races

Abstract

The fusion of ethnicity in human populations is becoming increasingly common, so the conventional definition of ethnicity is going to become deficient. The aim of this study was to investigate the hair properties which emerge from combinations of multiple races. Hair fibers collected from mixed-race subjects were investigated and classifications of hair shape as well as measurements of thickness, ellipticity and surface damage were carried out. The results show that hair shapes varied widely: straight hair and very curly hair often existed together on the heads of individuals with mixed ethnicity. Curly hair tended to be thicker than loose wavy hair. As for damage to the hair surface, the hairs of mixed-race subjects showed a very unique property in that they were much more severely damaged near the root (the proximal end) than the hairs of monoracial subjects. The hair shape (curly or loose wavy) was not related to the level of damage. The severe damage near the proximal end is thought to be caused by entanglement, due to the presence of various curl phases. This study reports the unique characteristics of hairs of subjects with mixed ethnicity, which have never been noted in the previous studies on subjects with a monoracial background.

Trichoscopic features of hair and scalp in noncomplaining individuals: A descriptive study

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Demographic Reporting and Phenotypic Exclusion in fNIRS

“…Even with spring-loaded grommets and tension tops on fNIRS caps, anecdotally, the signal quality for participants with coarse and/or curly hair is poor. As a result, individuals with coarse, curly, and dark hair -often people of African, African-American, and Caribbean descent -are excluded from fNIRS studies (14)(15)(16). Therefore, fNIRS datasets tend to underrepresent Black and Brown individuals, which supports the need for our review.…”

On Hair Care Physicochemistry: From Structure and Degradation to Novel Biobased Conditioning Agents

“…In this respect, hair can be categorized into three main groups: Caucasian, African, and Asian. Differences in chemical composition, structure, and properties have been studied for a long time [ 17 , 18 , 19 , 20 , 21 , 22 ]. The chemical composition of hair is reported to be independent of ethnic origin; all hair has the same chemical properties, i.e., protein composition [ 17 , 18 ].…”