Diversity of Hair Types by L’Oréal research

To characterize the diversity of hair types worldwide and identifytheir various properties, L’Oréal researchers have studied severaldifferent parameters: the shape of the hair shaft, the structure of the hair fibre components, the growth of the hair follicle and its pigmentation. They have drawn on techniques from biology, chemistry and biophysics, using optical and digital microscopic imaging.

Fifty percent of the world’s population has dark to very dark brown hair

As with skin, the diversity of hair types worldwide is reflected in a continuum of colour. An evaluation of natural hair colour based on volunteers’ geographical origin, age and sex showed that the natural colour of over 80% of the world’s population ranges [1] from black to light brown, and almost 50% of the population has dark or very dark brown hair. Blonde colours are mainly limited to Northern and Eastern Europe, while Asian, Melanesian and African hair is characterised by darker colours and less diversity.

From very straight to very curly hair

Hair shaft shape ranges from “straight with a circular cross-section” to “kinky with a highly elliptical cross-section and areas of torsion”. While shape is not specific to a given ethnic group, Asian hair is usually straight with a round cross-section, African hair tends to be twisted with a flattened cross-section and European hair is somewhere in between [2].

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