Fringe was an American native thing from what i 've read and seen of them in museums I feel they were an embellishment mostly. Native Americans did like to have nice things and their clothes were as much a status symbol as ours are now. They tied hair to them put beads on them and even dyed them. I also feel they probably helped break up the human outline so an asset to hunting in them. I'm sure they may wick some of the moisture away but not much although I have not found any definite proof of exactly why they used it.
If any of you folks are ever in CODY visit the museum, one the finest on western American history both native and not, plan on a two day visit!