© The Author(s) 2009

The main approach in studying both animal and human cogni-tion is to compare experimentally constituted groups on some cognitive task, with individual differences serving as “error variance ” only. There is a second approach to human cogni-tion, however—one that is based on the analysis of individual differences and their intercorrelations (for overviews, see Sternberg, 1999, 2004). In this approach, one looks for under-lying factors that might be responsible for individual variation in cognitive performance on multiple cognitive tasks. There has been very little work on the cognition of nonhu-man animals from the perspective of individual differences. A few animal studies have found positive correlations across various types of spatial orientation (maze) tasks (e.g., Crinella & Yu, 1995; Davenport, Hagquist, & Rankin, 1970; Thorn-dike, 1935), and a few other studies, mostly with mice an