Curly hair is primarily determined by genetics, specifically the shape of the hair follicle and the distribution of keratin, a structural protein, within the hair strand. If the follicle is asymmetrical, the hair grows in a twisted, curly shape.
People with curly hair often have oval or hooked follicles, while those with straight hair have round follicles. Additionally, the amount and pattern of disulfide bonds between keratin proteins in hair can influence curliness.
Environmental factors, hair care practices, and even humidity can also affect hair texture and the appearance of curls. Understanding the biological basis of curly hair helps appreciate its uniqueness and informs better care and styling practices.
