I think it like how africa people have little body hair.
Body hair is a way your body protect you from cold weather.
If it get too hot, body hair lost its purpose, so your body won't develope those anymore.
There are several cultures that genetically don't grow facial hair. Most native Americans didn't grow beards, it's all a genetics and evolution thing. I'm part Native American and I can barely grow a beard. Look for old pictures of native Americans and you'll almost never find one with facial hair.
Remember guys, this is Anna and Elsa's brother, because when their parent's 'died', really they were shipwrecked, had Tarzan and were eaten by Leopards.
When I first read this, I didn't understand that they were talking about his beard. Most men I know are walking Sasquatches & some actually do shave or shear their body hair down. And yes, there was one little part of me wondering about the loincloth.
Your hair also gets very thin if you have a lot of muscles. My brother trains his legs and you can see that there is hardly any hair on the upper leg, but has more hair around his ankles ( sorry, bad english)
Body hair is a way your body protect you from cold weather.
If it get too hot, body hair lost its purpose, so your body won't develope those anymore.
Translation: I'm 1/64th Cherokee.