Study of variability of cognitive performance in captive fallow deer (Dama dama) through g and c factors

Abstract

Psychometric studies reveal a variability that ranges between 30 and 75 % for different cognitive processes, both in humans and non-human animals. This variability has been ascribed to a “general intelligence” factor (g). Current studies implemented in non-human animals to identify individual differences in cognitive skills are still far from those applied in humans. We tested for cognitive performance in a fallow deer herd using a test battery of eight tasks based on measures for cognitive development in untamed confined wild animals: motor control, spatial memory, colour and tone discrimination and inversion, inhibitory control and symbol discrimination tests. g factor explained 60 % of the variability in cognitive performance. Significant correlations, both positive and negative, were found between the different cognitive processes studied. Likewise, the cognitive performance of the group was affected by a “collective intelligence” factor (c), inferred through variables describing the hierarchical structure of the studied population but which, however does not affect individual intelligence quotient of the members of the group.