Worldwide Diversity of Hair Curliness: A New Method of Assessment

This study developed a new method to objectively classify hair types based on specific shape criteria, independent of ethnic origin. Researchers measured four parameters related to hair curliness and kinking on hair from 2449 subjects across 22 countries. Using principal components analysis and hierarchical ascendant classification, they identified eight main hair types. This method proved more reliable than traditional verbal descriptions and better reflected the global diversity of hair shapes, potentially aiding in tracing mixed human origins.