International Journal of Comparative Psychology

Humans’ performance on most cognitive tasks are commonly regulated by an underlying latent variable (i.e., “general” intelligence), and the expression of this latent modulator of cognitive performance varies across individuals. While “intelligence” in humans is easily recognized, a precise definition of this trait has proven elusive, and has impeded efforts to compare the emergence of thi strait across species. Here we describe our efforts to characterize this cognitive trait in genetically heterogeneous laboratory mice. Using batteries of as many as eight learning tasks and various principal component analysis regimens, we have found a robust general factor that accounts fornearly 40% of the variance of individual animals across all tasks. This “” is not attributable to variations in stress reactivity or exploratory tendencies. However, like human intelligence, this general factor covaries with the efficacy of selective attention and working memory capacity. Importantly, we also find that general learning abilities covary with animals’ performance on novel tests of reasoning. In total, this work indicates that learning abilities, attentional control, andthe capacity for reasoning, features that constitute both colloquial and formal definitions of human intelligence, are commonly regulated in individual genetically heterogeneous mice. These results suggest an evolutionary conservation of the qualitative and quantitative properties of intelligence, and indicate that like humans, sub-human animals express individual differences in this trait.