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Life history and socioecology of infancy
Author(s) -
Helfrecht Courtney,
Roulette Jennifer W.,
Lane Avery,
Sintayehu Birhanu,
Meehan Courtney L.
Publication year - 2020
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/ajpa.24145
Subject(s) - investment (military) , context (archaeology) , developmental psychology , parental investment , population , life history theory , demography , psychology , ecology , biology , sociology , pregnancy , political science , paleontology , genetics , politics , offspring , law
Objectives Evolution of human maternal investment strategies is hypothesized to be tied to biological constraints and environmental cues. It is likely, however, that the socioecological context in which mothers' decisions are made is equally important. Yet, a lack of studies examining maternal investment from a cross‐cultural, holistic approach has hindered our ability to investigate the evolution of maternal investment strategies. Here, we take a systems‐level approach to study how human life history characteristics, environments, and socioecology influence maternal investment in their children. Materials and methods We test how infant age and sex, maternal age, parity, and child loss, and the composition of a child's cooperative breeding network are associated with maternal investment across three small‐scale (hunter‐gatherer, horticultural, and agropastoral), sub‐Saharan populations ( N = 212). Naturalistic behavioral observations also enable us to illustrate the breadth and depth of the human cooperative breeding system. Results Results indicate that infant age, maternal age and parity, and an infant's cooperative childcare network are significantly associated with maternal investment, controlling for population. We also find that human allomaternal care is conducted by a range of caregivers, occupying different relational, sex, and age categories. Moreover, investment by allomothers is widely distributed. Discussion Our findings illustrate the social context in which children are reared in contemporary small‐scale populations, and in which they were likely reared throughout our evolutionary history. The diversity of the caregiving network, coupled with life history characteristics, is predictive of maternal investment strategies, demonstrating the importance of cooperation in the evolution of human ontogeny.