Social Brain Hypothesis: Vocal and Gesture Networks of Wild Chimpanzees

Hdl Handle:
http://hdl.handle.net/10034/620258
Title:
Social Brain Hypothesis: Vocal and Gesture Networks of Wild Chimpanzees
Authors:
Roberts, Sam G. B.; Roberts, Anna I.
Abstract:
A key driver of brain evolution in primates and humans is the cognitive demands arising from managing social relationships. In primates, grooming plays a key role in maintaining these relationships, but the time that can be devoted to grooming is inherently limited. Communication may act as an additional, more time-efficient bonding mechanism to grooming, but how patterns of communication are related to patterns of sociality is still poorly understood. We used social network analysis to examine the associations between close proximity (duration of time spent within 10m per hour spent in the same party), grooming, vocal communication and gestural communication (duration of time and frequency of behaviour per hour spent within 10 meters) in wild chimpanzees. The results were not corrected for multiple testing. Chimpanzees had differentiated social relationships, with focal chimpanzees maintaining some level of proximity to almost all group members, but directing gestures at and grooming with a smaller number of preferred social partners. Pairs of chimpanzees that had high levels of close proximity had higher rates of grooming. Importantly, higher rates of gestural communication were also positively associated with levels of proximity, and specifically gestures associated with affiliation (greeting, gesture to mutually groom) were related to proximity. Synchronized low-intensity pant-hoots were also positively related to proximity in pairs of chimpanzees. Further, there were differences in the size of individual chimpanzees’ proximity networks - the number of social relationships they maintained with others. Focal chimpanzees with larger proximity networks had a higher rate of both synchronized low- intensity pant-hoots and synchronized high-intensity pant-hoots. These results suggest that in addition to grooming, both gestures and synchronized vocalisations may play key roles in allowing chimpanzees to manage a large and differentiated set of social relationships. Gestures may be important in reducing the aggression arising from being in close proximity to others, allowing for proximity to be maintained for longer and facilitating grooming. Vocalisations may allow chimpanzees to communicate with a larger number of recipients than gestures and the synchronized nature of the pant-hoot calls may facilitate social bonding of more numerous social relationships. As group sizes increased through human evolution, both gestures and synchronized vocalizations may have played important roles in bonding social relationships in a more time-efficient manner than grooming.
Affiliation:
University of Chester
Citation:
Roberts, S. G. B. & Roberts, A. I. (2016). Social brain hypothesis: vocal and gesture networks of wild chimpanzees. Frontiers in Psychology, 7(1756). doi:10.3389/fpsyg.2016.01756
Journal:
Frontiers in Psychology
Publication Date:
24-Nov-2016
URI:
http://hdl.handle.net/10034/620258
DOI:
10.3389/fpsyg.2016.01756
Additional Links:
http://journal.frontiersin.org/article/10.3389/fpsyg.2016.01756/full
Type:
Article
Language:
en
Description:
This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permission
EISSN:
1664-1078
Appears in Collections:
Psychology

Full metadata record

DC FieldValue Language
dc.contributor.authorRoberts, Sam G. B.en
dc.contributor.authorRoberts, Anna I.en
dc.date.accessioned2016-11-24T16:29:24Z-
dc.date.available2016-11-24T16:29:24Z-
dc.date.issued2016-11-24-
dc.identifier.citationRoberts, S. G. B. & Roberts, A. I. (2016). Social brain hypothesis: vocal and gesture networks of wild chimpanzees. Frontiers in Psychology, 7(1756). doi:10.3389/fpsyg.2016.01756en
dc.identifier.doi10.3389/fpsyg.2016.01756-
dc.identifier.urihttp://hdl.handle.net/10034/620258-
dc.descriptionThis Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permissionen
dc.description.abstractA key driver of brain evolution in primates and humans is the cognitive demands arising from managing social relationships. In primates, grooming plays a key role in maintaining these relationships, but the time that can be devoted to grooming is inherently limited. Communication may act as an additional, more time-efficient bonding mechanism to grooming, but how patterns of communication are related to patterns of sociality is still poorly understood. We used social network analysis to examine the associations between close proximity (duration of time spent within 10m per hour spent in the same party), grooming, vocal communication and gestural communication (duration of time and frequency of behaviour per hour spent within 10 meters) in wild chimpanzees. The results were not corrected for multiple testing. Chimpanzees had differentiated social relationships, with focal chimpanzees maintaining some level of proximity to almost all group members, but directing gestures at and grooming with a smaller number of preferred social partners. Pairs of chimpanzees that had high levels of close proximity had higher rates of grooming. Importantly, higher rates of gestural communication were also positively associated with levels of proximity, and specifically gestures associated with affiliation (greeting, gesture to mutually groom) were related to proximity. Synchronized low-intensity pant-hoots were also positively related to proximity in pairs of chimpanzees. Further, there were differences in the size of individual chimpanzees’ proximity networks - the number of social relationships they maintained with others. Focal chimpanzees with larger proximity networks had a higher rate of both synchronized low- intensity pant-hoots and synchronized high-intensity pant-hoots. These results suggest that in addition to grooming, both gestures and synchronized vocalisations may play key roles in allowing chimpanzees to manage a large and differentiated set of social relationships. Gestures may be important in reducing the aggression arising from being in close proximity to others, allowing for proximity to be maintained for longer and facilitating grooming. Vocalisations may allow chimpanzees to communicate with a larger number of recipients than gestures and the synchronized nature of the pant-hoot calls may facilitate social bonding of more numerous social relationships. As group sizes increased through human evolution, both gestures and synchronized vocalizations may have played important roles in bonding social relationships in a more time-efficient manner than grooming.en
dc.language.isoenen
dc.relation.urlhttp://journal.frontiersin.org/article/10.3389/fpsyg.2016.01756/fullen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectchimpanzeeen
dc.subjectgestural communicationen
dc.subjectvocal communicationen
dc.subjectbondingen
dc.subjectsocial network analysisen
dc.subjectsocial complexityen
dc.subjectcommunicative complexityen
dc.subjectproximityen
dc.titleSocial Brain Hypothesis: Vocal and Gesture Networks of Wild Chimpanzeesen
dc.typeArticleen
dc.identifier.eissn1664-1078-
dc.contributor.departmentUniversity of Chesteren
dc.identifier.journalFrontiers in Psychologyen
dc.date.accepted2016-10-25-
or.grant.openaccessYesen
rioxxterms.funderEconomic and Social Research Councien
rioxxterms.identifier.projectThis study was funded by the Economic and Social Research Council and a University of Stirling Fellowship to AR.en
rioxxterms.versionAMen
rioxxterms.licenseref.startdate2016-11-24-
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