A bear is the hair that grows on a human's chin, cheeks, neck, and the area above the upper lip (the opposite is a clean-shaven face). Typically, only post-pubescent males are able to grow beards.[dubious – discuss] When differentiating between upper and lower facial hair, a beard specifically refers to the facial hair on the lower part of a man's chin (excluding the moustache, which refers to hair above the upper lip and around it). The study of beards is called pogonology.