Grooming behaviour amongst the apes (the picking of
each other's
nits and cleaning of each other's
fur)
is thought to exercise a social function and contribute
towards the stability of the
social group. Looked at
in this light, it is often called
social grooming.
In a study by Robin Dunbar, it is noted that the size
of the social group is proportional to the time
spent on social grooming (amongst African monkeys
and apes.)
The study goes on to show that group-size in nonhuman
primates is a function of neocortical volume. Extrapolating from the human neocortical volume, a human group-size of about 200 is postulated.
The inference is made that language (which is processed
in the neocortex) is an evolutionary response designed to more efficiently time-manage the task of maintaining order within the social group.
In other words, language is simply the human equivalent of social grooming! The efficiency gained allows us to mainain (relative) order in much larger groups (even remotely, in this electronic age!)
This could explain why people like to gossip and, given the nit-picking origins, argue so much.
The abstract of Mr Dunbar's paper is at
http://www.linguistlist.org/issues/3/3-972.html
See Also: boundary posturing