Differences in childhood stress between Neanderthals and early modern humans as reflected by dental enamel growth disruptions

Abstract

Neanderthals’ lives historically portrayed as highly stressful, shaped by constant pressures to survive in harsh ecological conditions, thus potentially contributing to their extinction. Recent work has challenged this interpretation, leaving the issue of stress among Paleolithic populations highly contested and warranting in-depth examination. Here, we analyze the frequency of dental enamel hypoplasia, a physiological stress induced pathology, in the largest sample of Neanderthal and Upper Paleolithic dentitions investigated to date. To track potential species-specific patterns in the ontogenetic distribution of childhood stress, we present the first comprehensive Bayesian modelling of the likelihood of occurrence of individual and matched enamel growth disruptions throughout ontogeny. Our findings support similar overall stress levels in both groups but reveal species-specific patterns in its ontogenetic distribution. While Neanderthal children faced increasing stress starting with the weaning process and culminating in intensity post-weaning, physiological stress in Upper Paleolithic children was found to be limited to the period of weaning and substantially dropping right after its completion. These results might, at least in part, reflect differences in childcare or other behavioral strategies between the two taxa, including those that were advantageous for modern humans’ long-term survival.