Focusing on the technical limitations of adhering to conventional ethnic groups (African, Asian and Caucasian) in hair care, L’Oréal has established four hair shape descriptors for greater accuracy: curve diameter, curl index, number of waves and number of twists.
Recent research from the company has found that more than 80% of the world’s population has black to light brown hair, with nearly 50% having "dark or very dark brown" hair.
The findings were part of the beauty giant's study of the world's hair diversity. Among key findings, L’Oréal discovered:
- "African hair is characterized by both slow hair growth and low hair density"
- "Chinese hair also has a low density but grows very fast"
- "Caucasian hair grows at an intermediate rate per day and is very dense"
- Thick hair strands grow quickly, whereas thin hair strands grow more slowly
- Curly hair is more fragile than straight hair
Regarding shape, L'Oreal researchers found that, "The bulb of curly hair is curved, while that of straight hair is straight in shape. L’Oréal biologists also found that the shape of the bulb is linked to asymmetry in cell differentiation programs. The curve of the hair is created by an internal mechanical force."
Read the full research, including findings on hair shape, here.