Who Cares? How Caregivers Influence Communicative and Cognitive Development During Early Childhood

Abstract

The objective of this dissertation is to improve our understanding of how infants benefit from allomaternal care (AMC: care provided to infants by individuals other than the mother). Humans are unique among primates in our expression of extensive AMC. Infancy is a particularly intense period of risk for nutritional stress and mortality in humans, but AMC can help reduce this risk by supplementing the infant’s energy needs through food sharing. However, before age two, infants are not yet highly capable communicators. Thus, infants face a challenge in successfully recruiting AMC. However, when infants can successfully communicate their needs (e.g., cries communicating ‘I need food’ are met with mashed bananas), they are likely to experience reduced physical and psychological stress, while also gaining important practice communicating. Heightened exposure to AMC provides infants with an opportunity to interact with a larger variety of potential communicative partners, creating a a signal-rich environment through which AMC may influence communicative and cognitive development. This dissertation represents a novel, interdisciplinary approach to exploring the effects of AMC on early development before age two. Data were collected using questionnaires, in-lab assessments, daily diaries, and interviews from 102 typically-developing infants aged 13 to 18 months, and their mothers in Tucson, Arizona. Outcomes were assessed independently within linear regression models, followed by backward model selection to determine the best fitting model for each outcome. The results of this dissertation indicate that informal AMC, particularly in the form of Highly Involved Familial AMC and Household AMC, shapes early sensory and cognitive developmental processes. Additionally, informal care seems to be more important than formalized childcare in predicting outcomes within this age range. This dissertation enhances traditional perceptions of AMC by providing evidence that infants do gain important cognitive and communicative benefits when receiving frequent AMC during early development.