Well, the hairs on my scrotum are the same way as you described. I suspect everyone's are. As to why they are different than the rest of our pubic hair, I'm not sure, but I think it has to do with temperature regulation of the testicles for optimal sperm production (remember sperm production is best at a few degrees below body temperature). I think the scrotum hair helps the scrotum itself regulate the temperature better, so the hair is serving an active purpose.
| 
testicle hair colour 
Linear Mode
