Shaping dietary histories: Exploring the relationship between cranial modification and childhood feeding in a high-altitude Andean population (1100–1450 CE)

Abstract Cranial modification, the intentional reshaping of an infant’s head, was likely tied to notions of proper child-rearing in the ancient Andes. However, its relationship to other aspects of childhood experience and socialization is rarely interrogated. This study assesses childhood diet and weaning practices among 85 modified and unmodified individuals from the Colca Valley, Peru (1100–1450 CE), analyzing carbon and oxygen isotope ratios from 190 enamel carbonate samples from 110 teeth. Increasing δ13C values between cuspal and cervical enamel, and between early and later forming teeth, suggest that the diets of infants and children, regardless of social identity, were gradually supplemented by maize. Although average isotopic values do not differ systematically by site, sex, or presence or absence of cranial modification, modified individuals show greater variance in δ13C than unmodified individuals. Stable carbon isotope data from modified individuals with more than one tooth sampled further underscore the maintenance of distinct diets across juvenile life histories. This dietary diversity may be the outcome of more geographically expansive patterns of resource use that involved temporary residence outside of the valley. This interpretation follows from ethnohistorical models of vertical economy in the Andes, but requires further testing with other lines of isotope data.