Your hair, it’s color, texture, growth patterns and how much you have, is determined largely by your genes. It’s a ‘feature’ like which parent you resemble more, or how you have your grandfather’s nose for example. Familial tendencies like these, are similar to whether you have thicker hair or thinner hair. Also, hair growth patterns, like a receding hairline or widows peak, are ‘handed down’ from your genetics. This type of hair thinning is written into your DNA. Unfortunately, there’s isn’t anything (currently) that you can do to change this.