title: Social density processes regulate the functioning and performance of foraging human teams.
abstract: Social density processes impact the activity and order of collective behaviours in a variety of biological systems. Much effort has been devoted to understanding how density of people affects collective human motion in the context of pedestrian flows. However, there is a distinct lack of empirical data investigating the effects of social density on human behaviour in cooperative contexts. Here, we examine the functioning and performance of human teams in a central-place foraging arena using high-resolution GPS data. We show that team functioning (level of coordination) is greatest at intermediate social densities, but contrary to our expectations, increased coordination at intermediate densities did not translate into improved collective foraging performance, and foraging accuracy was equivalent across our density treatments. We suggest that this is likely a consequence of foragers relying upon visual channels (local information) to achieve coordination but relying upon auditory channels (global information) to maximise foraging returns. These findings provide new insights for the development of more sophisticated models of human collective behaviour that consider different networks for communication (e.g. visual and vocal) that have the potential to operate simultaneously in cooperative contexts.
authors.affiliation: Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: King
authors.affiliation: Biosciences, University of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, UK.
authors.forename: Julia P
authors.initials: JP
authors.lastname: Myatt
authors.affiliation: Biosciences, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP, UK.
authors.forename: Ines
authors.initials: I
authors.lastname: Fürtbauer
authors.affiliation: SENRG, Department of Experimental Psychology, South Parks Road, Oxford, OX1 3UD, UK.
authors.forename: Nathan
authors.initials: N
authors.lastname: Oesch
authors.affiliation: SENRG, Department of Experimental Psychology, South Parks Road, Oxford, OX1 3UD, UK.
authors.forename: Robin I M
authors.initials: RI
authors.lastname: Dunbar
authors.affiliation: School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK.
authors.forename: Seirian
authors.initials: S
authors.lastname: Sumner
authors.affiliation: Structure &Motion Laboratory, Royal Veterinary College, Hatfield, Hertfordshire, AL9 7TA, UK.
authors.forename: James R
authors.initials: JR
authors.lastname: Usherwood
authors.affiliation: Department of Computer Science, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Hailes
authors.affiliation: College of Engineering, Swansea University, Bay Campus, Fabian Way, Swansea SA1 8EN.
authors.forename: M Rowan
authors.initials: MR
authors.lastname: Brown
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D000704:Analysis of Variance; D003299:Cooperative Behavior; D003657:Decision Making / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D006126:Group Processes; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology; D012919:Social Behavior; D055815:Young Adult