Family Matters: Tracing the Social Cognitive Development of Kinship Understanding

Abstract

Kinship provides the major framework for social organization, but when do infants and children develop understanding of these social relationships and how they affect social behaviors? This dissertation proposes that caregiving relations are relevant from infancy in humans, as it is across many species in the animal kingdom, and may be a dimension that is factored into a candidate core knowledge domain for reasoning about social partners, along with additional relevant social information like dominance. Furthermore, I propose that kin relatedness is relevant to children’s social decision making when deciding with whom and when to help, share, or cooperate, consistent with evolutionary psychology’s proposal of a welfare tradeoff psychology and cognitive developmental psychology’s proposal of a naïve utility calculus, as a component of reward—where individuals closer in relatedness and higher in social value are more rewarding to help than those more distantly related. This dissertation explored these theories in three lines of research. First, in a series of six looking-time experiments using animated events, we found that 15- to 18-month-old infants tracked relationships in caregiving networks—but not a social context among peers—and expected babies soothed by the same adult or two adults who soothed the same baby to affiliate with one another more so than babies or adults who did not share a social connection (Paper 1). This suggests that caregiving—which is often but not exclusively, or specifically, kin—is incorporated into infants’ social inferences. Next, we tested through three looking-time experiments how five-month-old infants evaluate caregiving behaviors in animated events and found that infants showed a preference for an adult who responded rather than avoided a crying baby, providing evidence that young infants are sensitive to and evaluate an adult’s responsiveness as a caregiver, further supporting early integration of caregiving information into social evaluations (Paper 2). Finally, in three experiments, we investigated three- to five-year-old children’s explicit conceptual understanding of kin and non-kin relationships to test if children identify kinship as a relevant social dimension and if children’s expectations for social interactions change when kin relations are involved, potentially benefitting related over unrelated others (Paper 3). We found that children had clear distinctions between familiar and unfamiliar relations—sibling versus stranger and friend versus stranger—but did not have as clearly delineated understanding in answering conceptual questions about the relations, or expectations when asked about hypothetical sharing scenarios between siblings and friends. This pattern of results is consistent with kinship affecting social decisions in addition to other factors like the likelihood of an individual reciprocating—a quality friends may have more than siblings. Together, these three papers provide evidence that infants and children are incorporating caregiving (Papers 1-2) and kin relatedness (Paper 3) into their social inferences and decision making. A candidate core knowledge domain of social partners may include information about caregivers: their likely affiliative partners (Paper 1) and their responsiveness to a crying baby (Paper 2). In addition, children made different sharing decisions based on who was involved (Paper 3), suggesting that social value and kin relatedness weighs into a welfare tradeoff psychology and/or the reward of an action in a naïve utility calculus. Finally, I discuss ongoing research and remaining open questions that further these hypotheses.