title: Reflections of the social environment in chimpanzee memory: applying rational analysis beyond humans.
abstract: In cognitive science, the rational analysis framework allows modelling of how physical and social environments impose information-processing demands onto cognitive systems. In humans, for example, past social contact among individuals predicts their future contact with linear and power functions. These features of the human environment constrain the optimal way to remember information and probably shape how memory records are retained and retrieved. We offer a primer on how biologists can apply rational analysis to study animal behaviour. Using chimpanzees (Pan troglodytes) as a case study, we modelled 19 years of observational data on their social contact patterns. Much like humans, the frequency of past encounters in chimpanzees linearly predicted future encounters, and the recency of past encounters predicted future encounters with a power function. Consistent with the rational analyses carried out for human memory, these findings suggest that chimpanzee memory performance should reflect those environmental regularities. In re-analysing existing chimpanzee memory data, we found that chimpanzee memory patterns mirrored their social contact patterns. Our findings hint that human and chimpanzee memory systems may have evolved to solve similar information-processing problems. Overall, rational analysis offers novel theoretical and methodological avenues for the comparative study of cognition.
authors.affiliation: Department of Psychology and Center for Brain, Biology and Behavior, University of Nebraska-Lincoln, Lincoln, USA; Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: Jeffrey R
authors.identifier: 0000-0003-2375-1360
authors.initials: JR
authors.lastname: Stevens
authors.affiliation: Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, Berlin, Germany; Faculty of Business and Economics, University of Lausanne, Lausanne, Switzerland.
authors.forename: Julian N
authors.initials: JN
authors.lastname: Marewski
authors.affiliation: Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, Berlin, Germany; Department of Psychology, Syracuse University, New York, NY, USA.
authors.forename: Lael J
authors.initials: LJ
authors.lastname: Schooler
authors.affiliation: School of Human Evolution and Social Change, and Institute of Human Origins , Arizona State University , Tempe, AZ , USA.
authors.forename: Ian C
authors.initials: IC
authors.lastname: Gilby
keywords: chimpanzees; comparative cognition; forgetting; memory; rational analysis; social contact