Exploring Childhood Stress: Contrasting Experiences between Neanderthals and Paleolithic Modern Humans
Children of Neanderthals, who lived up to around 40,000 years ago, and modern humans of the Late Paleolithic period between 50,000 and 12,000 years ago were probably exposed to comparable stress, but the highest intensity was in different phases of development. This was the result of an examination of teeth, the structure of which reflects periods of stress caused by illness and malnutrition during the early years of life. The study was carried out by Laura Limmer, Dr. Sireen El Zaatari and Professor Katerina Harvati from the Institute of Scientific Archaeology at the University of Tübingen together with international colleagues. The researchers suspect that modern humans may have had better strategies than Neanderthals to reduce the stress on their children during difficult phases of development. Their study was published in the journal Scientific Reports.
The paleoanthropologists examined 867 teeth, of which 423 came from 74 Neanderthal individuals and 444 from 102 modern humans from the Late Paleolithic period. The teeth were found at 56 different archaeological sites in western Eurasia. Both milk teeth and permanent teeth are formed in childhood. “When children experience infections or other diseases or the nutritional situation is poor, malformations of the tooth enamel occur. Since the permanent teeth do not continue to grow later, we can also recognize such defects in the teeth of adults,” explains Sireen El Zaatari. The regular formation of enamel on the teeth makes it possible to link such events to certain stages of development in children.
Possible strategies
Overall, the Neanderthals and modern humans from the Late Paleolithic period were exposed to similar levels of stress in their early childhood, the researchers found. “However, we observed a different distribution of enamel defects across the developmental phases of the children: in modern humans, enamel defects were more likely to occur at the age when the children were weaned,” says Limmer. In the children of Neanderthals, enamel defects also became more common at the time when weaning presumably began, but the peak exposure to physical stress occurred in a developmental phase after this period.
The researchers assume that children in the Paleolithic era were exposed to increased stress due to weaning, because increasing energy requirements during growth coincided with an increasing risk of malnutrition. “It is possible that modern humans gained advantages over Neanderthals by supporting their children better during this difficult phase, for example by protecting the children for longer and providing them with better food,” says El Zaatari. It is conceivable that this behavior was a building block in the development that allowed modern humans to survive to this day and the Neanderthals to die out. “It has often been said that Neanderthals lived in a particularly harsh climate with low temperatures and failed because of it. However, over a certain period of time Neanderthals and modern humans were exposed to the same climatic conditions, so we are also investigating other explanations.”