0:03NARRATOR: A session of
grooming calms the nerves.
0:09It also keeps
parasites to a minimum
0:11as well as strengthening
relationships and maintaining
0:14cohesion in the group.
0:18And it is a useful
tool for currying favor
0:21with troop members
of higher rank,
0:24with subordinates often
grooming their superiors.
0:35It's also believed to have
another important function.
0:39Violent encounters
trigger the release
0:41of stress hormones in females.
0:44These hormones can interfere
with reproductive processes
0:48and reduce fertility.
0:51Grooming releases
endorphins that suppress
0:54the production of
stress hormones,
0:58ensuring healthy breeders.
