Conjugal families are often assumed to be building blocks of human societies and the primary site of childrearing in traditional communities. Alternatively, Kristen Hawkes (Univ of Utah) contends that the Grandmother Hypothesis draws attention to other relationships likely fundamental in the evolution of our lineage. Persistent ties that crosscut conjugal families are implied by our cooperative childcare, distinctive prosociality, and extraordinary operational sex ratios. These high operational sex ratios also affect the way men negotiate with other men, which in turn affects the economics of childrearing. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 28036]