INTRODUCTION

This chapter considers cognition in great apes as integrated systems that orchestrate the many abilities that great apes express, systems for which satisfactory characterizations remain elusive. In part, difficulties owe to research trends. Empirical studies have been guided by diverse and sometimes contradictory models, questions, measures, tasks, and living conditions. Performance levels have proven inconsistent across individuals, rearing conditions, and testing conditions, and evidence is patchy across species for virtually any facet of cognition. Evidence on wild great apes, the most important from an evolutionary perspective, is especially patchy because research has favored captives; much of what is available was collected for other purposes, so it was neither described nor analyzed with cognition in mind. The issues at stake are also hard–felt ones that touch on the human–nonhuman boundary, so entrenched beliefs infect how the literature is interpreted and even what of it is read.

Attempts have none the less been made to develop an integrated model of great ape cognition using available evidence. They include both edited survey volumes (Matsuzawa 2001a; Parker, Mitchell & Miles 1999; Russon, Bard & Parker 1996) and integrative reviews, three of the latter as major books (Byrne 1995 (RWB), Parker & McKinney 1999 (P&M); Tomasello & Call 1997 (T&C)) and others as articles (e.g., Byrne 1997; Suddendorf & Whiten 2001; Thompson & Oden 2000; Whiten & Byrne 1991). My aim is not to analyze this terrain, yet again, in detail, but to offer a compact mise à date to ground evolutionary reconstruction.