Exploring the relationship between personality, interest, and success in cognitive enrichment in western gorillas (Gorilla gorilla)

Environmental enrichment has become a valuable tool for promoting the welfare of primates in captivity. In this context, research on personality can help clarify how individual differences influence engagement with environmental enrichment at the individual level. Numerous studies suggest that specific personality traits may be associated with heightened motivation to explore or solve environmental enrichments tasks. Nevertheless, this relationship remains unexplored within the genus Gorilla. Addressing this gap may contribute to the development of enrichment programs tailored to individual needs. In our study, we examined the relationship between personality, interest, and success in completing a cognitive feeding enrichment task in 17 zoo-housed western gorillas (Gorilla gorilla). The enrichment task involved retrieving food from a tube presented in a social context. Each session consisted of a 30-minute recording of a gorilla performing the enrichment task, with three sessions per individual. We conducted personality assessments using the Gorilla Behavior Index questionnaire, which comprised 25 adjectives. Exploratory factor analysis revealed three factors that accounted for 74% of the variance. We found a negative association between the Protectiveness factor and success rate in the enrichment task. In contrast, we found no evidence that personality factors influenced interest in the enrichment. Additionally, success increased across sessions, and females extracted food more efficiently than males. Overall, our findings suggest that personality traits and sex play an important role in explaining individual differences in engagement with and outcomes of enrichment tasks in captive gorillas.