Hair texture is largely governed by genetics. Genes play a role in determining if a person has straight, curly, or wavy hair and even the thickness of hair strand is controlled by genetic factors. For example, the polymorphic forms of the two genes, EDAR and FGFR2, is said to control the differences in thickness of hair among Asian populations. While polymorphism in TCHH gene, is responsible for differences in hair texture in people of north European descent.