Attempts to describe the latent structure of human infant temperament have led some to suggest the existence of three major dimensions. An earlier exploratory factor analysis (EFA) supported a triadic structure of temperament in week-old rhesus monkey infants, paralleling the structure in human infants. This study sought to confirm the latent triadic structure of temperament across the first month of life in a larger sample of rhesus monkey infants (N = 668), reared by their mothers or in a neonatal nursery. A weekly behavioral assessment was obtained during the first month of life using a subset of items from the widely utilized Infant Behavioral Assessment Scale (IBAS), an instrument designed to measure temperament in infant monkeys. Using the latent constructs proposed by the earlier EFA (Orienting/Regulation, Negative Affectivity, Surgency/Extraversion), multi-group, multi-time point confirmatory factor analyses were conducted to confirm the latent temperament structure across rearing groups at each time point (weeks 1-4). Results confirm and extend those of the earlier EFA: latent Orienting/Regulation, Negative Affectivity, and Surgency/Extraversion constructs were present across the rearing groups at each time point, with the IBAS items consistently loading onto the latent factors to a similar degree across rearing groups at each time point. These findings suggest foundational evolutionary roots for the triadic structure of human infant temperament, but that its behavioral manifestations vary across maturation and rearing condition. Similarities in latent temperament structure in humans and a representative nonhuman primate highlights the potential for utilizing translational nonhuman primate models to increase understanding of human temperament.
Keywords: infant temperament; multi-group longitudinal confirmatory factor analysis; multi-group multi-time confirmatory factor analysis; neonatal behavioral assessment scale; rhesus monkey; triadic structure of temperament.
© 2020 Wiley Periodicals, Inc.