Question: why do we have hair on our arms? (its useless)

Helen O'Connor answered on 22 Jun 2011:

I think we actually have hair everywhere on our body apart from the soles of our feet and the palms of our hands – its just that in some places it is really fine and we don’t notice it as much.

Luckily we don’t grow hair everywhere that’s like the hair on our head. All our hair has an active and a resting phase. The active phase determines the length of their hair and then when hair has got to its maximum length, it goes into the resting phase where growth slows down and hair eventually falls out.

Your body hair’s active phase lasts a couple of months, and the hair on your heads active phase can last a few years. This explains why your head hair is longer than your body hair.

Compared to most mammals, we are relatively bald – in fact I think that only elephants and rhinos have as little hair as we do!

And be thankful that you don’t have hypertrichosis, or “werewolf syndrome” http://en.wikipedia.org/wiki/Hypertrichosis

Im not a biologist, so I am not quite sure WHY we have it, but there is another question here https://nickelj11.iasuk.ddev.site/2011/06/why-do-we-have-hair-all-over-our-bodybut-not-our-hand-or-inside-of-our-arms