Developmental trajectories of cognitive traits in meerkats match socio-ecological demands

Understanding cognitive development is fundamental for explaining variation in adult cognitive phenotypes, and thus the processes driving cognitive evolution. The ontogeny of cognitive traits is likely influenced by both population-wide pressures, such as ecological demands, and individual-specific factors, including early life experiences. To properly investigate cognitive variation, we must therefore identify species-level developmental trajectories and individual variation from normative ontogeny. We studied the ontogeny of three cognitive traits--inhibition control, spatial cognition, and physical problem-solving skills--in 28 wild meerkats (Suricata suricatta) from eight litters (seven groups). Our longitudinal study followed individuals from early life to nutritional independence and into sub-adulthood. We found that rates of development (learning curves) varied among traits, reflecting the timing of socio-ecological pressures in this species. Performance of cognitive traits did not correlate over ontogeny nor at specific time points, suggesting independent processes underlying each measured trait. While the development of inhibitory control appeared conserved, that of spatial cognition and physical problem-solving showed substantive individual differences. Furthermore, only physical problem-solving showed consistency in performances over time, emerging near nutritional independence, reflecting its ecological importance early in life. Future research should determine the drivers of individual developmental variation and how such differences translate into fitness consequences.