Bioarchaeological studies from the Late Holocene in central California have revealed changing patterns of interpersonal violence through time, from a higher prevalence of cranial vault trauma and trophy- taking early in time followed by a shift toward more projectile point injuries later. These studies indicate that temporal patterns of violence in the San Francisco Bay Area do not correspond to climatic changes (MCA) and to the adaptation to resource depression in the form of intensification models. Rather, these changes may have been due to population movement and sociopolitical factors. Mortuary studies reveal a change in sociopolitical structure towards inequality in wealth distribution, pointing to a more hierarchical society during the Middle period, coinciding with a higher rate of trophy taking. At this point, the Meganos intrusion, the population movement in the Middle period from the Sacramento-San Joaquin Delta, corresponds to a significant change in mortuary behavior, along with disruption of existing trading networks. The changes in societal structure and behaviors evidenced in the archaeological record point to aspects of reaction, adoption, or imposition, or some combination, in the transformation process. Similarly, the introduction of the bow and arrow in the transition to the Late period marks another significant change in the type of injuries, and though the levels of inter-personal aggression fall from those encountered in the transition to the Middle period they do not return to the Early period levels.

Viviana Bellifemine is currently a lecturer at San Jose State University. She received her M.A. in Archaeology from San Jose State University and later coursed Ph.D. studies at Cambridge University (UK). For fifteen years she worked in cultural resource management in central California. She specializes in the study of mortuary practices in prehistoric California cultures, as well as studying the mortuary behaviors of Inka and pre-Inka populations of the Cuzco region, Peru. She has contributed to multiple scholarly articles, book chapters, conference presentations, and CRM monographs.