eli5: How come men have do deal with balding on their heads, but not in their beards (or anywhere else for that matter)?

Question

I’ve seen so many old guys rocking beautiful beards yet their head is literally devoid of hair. How come balding doesn’t affect beards or the rest of their body?

In: Biology

Answer 1

Testosterone impacts hair follicles in a patterned fashion across the body. This leads to the beneficial result of sexual signaling — men high in testosterone physically look different from men low in testosterone. It’s similar to sexual dimorphism (how men look different from women).

It is, counter-intuitively, a form of peacocking, though one that doesn’t carry off as well in our youth-obsessed culture where the appearance of young men (with a full head of glossy hair) is weirdly idealized throughout life.