It seems in this tribe that the young boys go through a premature aging process. Perhaps this is done as a way to make a child warrior look more experienced and fearsome, but I must admit it was also slightly comical. (Of course it would be less amusing if spears were being pointed in my direction.)
It appears that each boy has the middle of his head shaved to give a bald spot, and then this hair is mixed with glue and applied to the face to give beards, or Wolverine style sideburns.
Some boys seemed to love the new look, others were decidedly less sure.