Signaling context modulates social function of silent bared-teeth displays in rhesus macaques (Macaca mulatta).
Level 5 - mechanism / opinion, no new human data
Animal behavioral study (non-human primate research)
PubMed 24038330 · doi:10.1002/ajp.22214
What was done
Observers evaluated the usage and social context of silent bared-teeth displays (SBT) across seven captive groups of rhesus macaques (Macaca mulatta). The study examined peaceful versus conflict signaling contexts in relation to grooming, severe aggression, signaler-receiver sex, rank difference, body size, and subsequent withdrawal behavior (staying versus leaving).
What was found
The abstract reports directional behavioral patterns without numerical figures or statistical effect sizes. Peaceful SBTs were directed most often to male receivers by both male and female signalers, whereas conflict SBTs were given primarily by female signalers to receivers of both sexes; male signalers rarely directed SBTs to females. Severe aggression occurred less frequently among dyads using peaceful SBTs compared to conflict SBTs. Grooming occurred more frequently among dyads exhibiting peaceful SBT-stay signals than among those using peaceful SBT-leave signals or conflict SBTs.
Why it matters
This study shows that communicative signals in rhesus macaques are context-dependent, with peaceful and conflict bared-teeth displays serving distinct behavioral functions rather than representing a single uniform message.
Limits
The study was conducted entirely in captive groups, which may constrain or modify social interaction patterns relative to wild populations. The abstract does not report the total number of individual macaques, the volume of observed interactions, or any numerical point estimates and confidence intervals.
Cited by
- contradicts In macaque monkeys, bearing teeth signals aggression rather than friendliness.