Before the expansion of the Inka empire, the Late Intermediate Period was marked by political upheaval and the emergence of new cultural practices. In “Ethnogenesis and Social Difference in the Andean Late Intermediate Period (AD 1100-1450): A Bioarchaeological Study of Cranial Modification in the Colca Valley, Peru,” published in Current Anthropology, Matthew C. Velasco examines how the prevalence and evolution of cranial modification practices during the Late Intermediate Period influenced ethnic identity formation in Peru’s Colca Valley. In the study, Velasco explores how head-shaping practices may have enabled political solidarity and furthered social inequality in the region.