Silvering with age is also prominent in the European badger. That's the frosty hair used in shaving brushes and men's hat decorations. We can speculate on how graying became connected up with signals of social status. It is in many species a deterioration which accompanies senility. Judging from the uses of graying among the primate species just discussed and its occurrence and location, we can conclude that both of these forces have been at work.
Chimps offer an interesting medium to study the evolution of status graying.
Many primates have contrastingly colored snouts, beards, and cheek whiskers. Among some they are white. Some chimps have white hair on the snout from birth and others gray around the mouth with age. Though we all pretty much know qualitatively the age sequence of graying and the patterns in which it occurs, let's map a little more precisely the various parameters of the graying process. Humans do not gray randomly, but in a specific pattern.