Socially transmitted diffusion of a novel behavior from subordinate chimpanzees

Chimpanzees (Pan troglodytes) demonstrate much cultural diversity in the wild, yet a majority of novel behaviors do not become group‐wide traditions. Since many such novel behaviors are introduced by low‐ranking individuals, a bias toward copying dominant individuals (“rank‐bias”) has been proposed as an explanation for their limited diffusion. Previous experimental work showed that chimpanzees (Pan troglodytes) preferentially copy dominant over low‐rank models. We investigated whether low ranking individuals may nevertheless successfully seed a beneficial behavior as a tradition if there are no “competing” models. In each of four captive groups, either a single high‐rank (HR, n = 2) or a low‐rank (LR, n = 2) chimpanzee model was trained on one method of opening a two‐action puzzle‐box, before demonstrating the trained method in a group context. This was followed by 8 hr of group‐wide, open‐access to the puzzle‐box. Successful manipulations and observers of each manipulation were recorded. Barnard's exact tests showed that individuals in the LR groups used the seeded method as their first‐choice option at significantly above chance levels, whereas those in the HR groups did not. Furthermore, individuals in the LR condition used the seeded method on their first attempt significantly more often than those in the HR condition. A network‐based diffusion analysis (NBDA) revealed that the best supported statistical models were those in wh...

Source: American Journal of Primatology - February 7, 2017 Category: Psychiatry & Psychology Authors: Stuart K. Watson, Lisa A. Reamer, Mary Catherine Mareno, Gillian Vale, Rachel A. Harrison, Susan P. Lambeth, Steven J. Schapiro, Andrew Whiten Tags: RESEARCH ARTICLE Source Type: research