International Journal of Comparative Psychology

Field studies have been, and continue to be, important contributors to the

understanding of great ape cognition-especially with regard to questions of cognitive

ecology or the key cognitive challenges in the evolution of primate intelligence. They

are also critical to resolving a current debate, whether human enculturation boosts great

apes' cognition, because only studies of problem-solving in feral contexts can resolve

the question of whether abilities are higher in enculturated than non-enculturated great

apes. To this debate, this paper offers findings from observational field studies on freeranging

rehabilitant orangutans' cognitive capabilities, as revealed in their food

processing and arboreal positioning, and on the possible social transmission of that

expertise. These findings are combined with published findings on wild and

enculturated great apes as a basis for assessing the effects of human enculturation on

great ape cognition. This assessment joins several others in showing that free-ranging

great apes independently achieve cognition of the same order of complexity as

enculturated great apes, in concluding that claims for the effects of human enculturation

are likely inflated, and in suggesting that the basis for the effectiveness of human

enculturation is that great apes normally "enculturate" themselves.