The average human body is covered in millions of hair follicles, and follicle density is particular dense on the head. Whether those follicles are actively pushing out medulla, cortex and cuticle, however, is another story entirely.
In the latest installment of AsapSCIENCE, Mitchell Moffit and Gregory Brown explore the genetics and heritability of hair loss and male pattern baldness — including why your maternal grandfather is a good place to look for answers when you start wondering about the future of your own head of hair. That said, the status of gramps' coif is hardly the last word when it comes to the future of your own head; as the video points out, there are plenty of other factors involved; those with cue-balled forebears need not abandon all hope.