The structure of ape (hominoidea) intelligence.

We used contemporary psychometric theory of intelligence and confirmatory factor analysis to reanalyze data obtained on samples of nonhuman primates administered the Primate Cognition Test Battery. Our main goals were to interpret stability of the Primate Cognition Test Battery tasks and factors over time and to determine whether the cognitive factors that emerge from confirmatory factor analysis for apes can be interpreted from the perspective...