Foundations of cumulative culture in apes: improved foraging efficiency through relinquishing and combining witnessed behaviours in chimpanzees (Pan troglodytes)

Abstract

A vital prerequisite for cumulative culture, a phenomenon often asserted to be unique to humans, is the ability to modify behaviour and flexibly switch to more productive or efficient alternatives. Here, we first established an inefficient solution to a foraging task in five captive chimpanzee groups (N = 19). Three groups subsequently witnessed a conspecific using an alternative, more efficient, solution. When participants could successfully forage with their established behaviours, most individuals did not switch to this more efficient technique; however, when their foraging method became substantially less efficient, nine chimpanzees with socially-acquired information (four of whom witnessed additional human demonstrations) relinquished their old behaviour in favour of the more efficient one. Only a single chimpanzee in control groups, who had not witnessed a knowledgeable model, discovered this. Individuals who switched were later able to combine components of their two learned techniques to produce a more efficient solution than their extensively used, original foraging method. These results suggest that, although chimpanzees show a considerable degree of conservatism, they also have an ability to combine independent behaviours to produce efficient compound action sequences; one of the foundational abilities (or candidate mechanisms) for human cumulative culture.

Acquisition of a socially learned tool use sequence in chimpanzees: Implications for cumulative culture

“…Previous research has found that orangutans and chimpanzees are more likely to flexibly modify their behavior when known behaviors become ineffective (Lehner et al, 2011; Manrique et al, 2013) or difficult to perform (Davis et al, 2016). Accordingly, long bendy tool use may have been facilitated in Phase 3 as past, suboptimal behaviors became obsolete or more difficult to perform with this simulation of such an ecological change.…”

“…This is of interest given that one driver of behavioral modification is environmental fluctuation or risk, which may encourage behavioral change when past behaviors become inefficient or redundant (Buchanan, O’Brien, & Collard, 2015; Collard, Buchanan, & O’Brien, 2013; Collard, Kemery, & Banks, 2005; Smaldino & Richerson, 2013). Behavioral change in nonhuman primates who otherwise show conservative behavior (Marshall-Pescini & Whiten, 2008) has been found to be facilitated as past behaviors become obsolete (Lehner et al, 2011; Manrique, Volter, & Call, 2013) or difficult to perform (Davis, Vale, Schapiro, Lambeth, & Whiten, 2016). Again, during this phase, the three seeded groups had access to a trained model and the non-seeded groups did not.…”

Lack of conformity to new local dietary preferences in migrating captive chimpanzees

“…First, there is a countervailing tendency in chimpanzees for conservative behaviour, that is, to persevere with a known behaviour despite the availability of a behavioural alternative that is within participants’ capacity to learn, noted in several recent studies (Haun et al, 2014; Hrubesch, Preuschoft, & van Schaik, 2009; Marshall-Pescini & Whiten, 2008; although see Manrique, Volter, & Call, 2013 and Davis et al 2016, for cases of flexible behaviour in chimpanzees when past solutions become unavailable or very costly). However, as local-majority and migratory-minority chimpanzees proceeded to sample both previously Pal and unPal foods, social information was sufficient to overcome the conservative Pal food preference documented in control chimpanzees.…”

Cumulative cultural learning: Development and diversity

“…Human psychological flexibility provides the foundation for cultural diversity and is a prerequisite for cumulative culture. It allows humans to build upon established behaviors by relinquishing old solutions and flexibly switching to more productive or efficient ones (128).…”

“…Acquiring the behavior of other group members may be the function of an individual-level adaptation for imitation in our species. Thus, the transmission of cumulative culture across generations can be seen, in part, as a product of our propensity for imitative flexibility (128).…”