A biogeochemical approach to examining sub-adult diet and the weaning process at Neolithic Tepecik-Çiftlik, Türkiye

Tepecik-Çiftlik, a Neolithic settlement located in the Cappadocia region of Central Anatolia, within the boundaries of Niğde province in modern Türkiye is crucial for helping us to better understand social behaviour and human mobility in the Neolithic, as well as relations between different groups. To investigate dietary habits, subsistence practices, and intra-societal variations stable carbon and nitrogen isotope ratio analysis has been conducted on the Neolithic human and faunal population. Further to this, 21 sub-adults were also sampled for stable carbon and nitrogen isotope ratio analysis to examine sub-adult diet, complementary feeding, and the cessation of breastfeeding as part of the weaning process. This isotopic investigation into the weaning process is complemented by a previously conducted study using Sr/Ca ratios from bone apatite of the same population. The δ¹³C values of the sampled sub-adults range from −19.8 ‰ to −19.0 ‰ and the δ¹⁵N values range from 8.0 ‰ to 15.2 ‰. The isotopic data suggest a very early onset of complementary feeding (ca. 0.2 years of age) and a brief breastfeeding period, relative to other prehistoric populations. The cessation of breastfeeding and this very brief weaning process was likely completed by ca. 1–1.5 years old. This early commencement of complementary feeding was most probably a deliberate social and cultural choice, supported by the presence of bowls and feeding spoons in the graves of very young babies and infants. However, this cultural choice may also have affected the mortality profile of the Neolithic population.