system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do guys grow hair on their chests and backs, but girls have none? What's the point of even having any in those places?
gpt
Women do have hair on their chests and backs, but men's body hair is longer, darker and coarser, thus more visible.  

There are many theories about why we have body hair, including insulation and additional tactile feeling:

>Androgenic hair extends the sense of touch beyond the surface of the skin into the air and space surrounding it, detecting air movements as well as hair displacement from contact by insects or objects.

See Androgenic hair on Wikipedia.