Social Conventions in Wild White-faced Capuchin Monkeys
-five behavioral patterns qualified as social traditions: handsniffling, sucking of
body parts, and three types of games.
-some conventions independently invented in virtually identical form at multiple
-extinction of several conventions observed during course of study, rarely last
longer than 10 years.
-hypothesized that the monkeys are using these group or clique specific social
conventions to test the quality of social relationships
-to understand socioecological factors, it is necessary to look beyond
-capuchin monkeys: new world
-independently evolved many traits that are present in humans and
-large brain-body ratio, omnivorous, extractive foraging, sometimes share
food, skilled tool users, nonconceptive sex, alloparenting, lethal agg,
complex social relationships
-most models of social transmission are about behaviors performed by
single individuals that have a clear adaptive function
-social conventions are necessarily performed dyadically rather than by
single individuals, the role that social conventions play in the behavioral
biologu of the animals is different from the role of foraging related
behaviors: transmissions different than the more frequently modeled ones.
Identifying a Tradition
-behavioral tradition: a practice that is relatively long-lasting and shared
among members of a group, each new practitioner relying to some extent
upon social influence to learn to perform it. Three criteria:
-inter-group variation: the behavior in question must be present in
at least one social group and absent in at least one group. must be
seen at a rate of at least once per 100 hours of observation, and
must be performed by at least three individuals. absent: must never
have been seen, and observed for at least 250 hours.
-expansion: behavior must exhibit an expansion in the number of
performers over time (unless all group members perform it)
-durability: the behavior must be durable. we arbitrarily coded
behaviors as durable if they were observed spanning at least a six
The Study Species
-Capuchin: long lived, prolonged juvenile period, multimale, multifemale
groups, female philopatric, males migrate multiple times and form
migration alliances of 2-4 males that have affiliative relationships and
migrate together, invading new groups and evicting some or all of the
resident males. female female dyads tend to have the closest bonds. alpha male central role, subordinate males active social life and
-not universal across study groups. invented or imported multiple times.
once established, not in permanent repertoire.
-precise form of handsniffing varied somewhat from site to site, the
successful propagation of han