Lindsey Powell (CBMM Thrust 1, CBMM Thrust 4)
Topic: Infants' Understanding of Social Actions
Abstract: Intentional human actions fall into at least two partially separable classes -- actions aimed at interacting with objects and actions aimed at interacting with people. The principles by which these two types of actions are effective vary substantially, and thus the means by which people recognize object- vs. socially-directed actions and the inferences they make when observing them are likely to differ substantially. Research with both infants and adults suggest that they use a principle of rational efficiency with respect to physical constraints in identifying actions aimed at object-based goals. In contrast, socially meaningful actions (including gestures, vocalizations, and ritual behaviors) are typically inefficient as means toward physical outcomes. Instead, they gain effectiveness by being shared by, and thus mutually interpretable to, both the actor and the social partner toward whom the action is directed. Building on past work showing that infants expect members of social groups to engage in the same behaviors, I will present several completed studies supporting the conclusion that infants only expect such shared behaviors (a) when the actions are not efficient means toward external changes in the world, and (b) when infants have previously seen two social partners both engage in the action. These results suggest that even in the first year of life infants have some understanding of the principles by which social actions work, as well as an expectation that they will be non-overlapping with object-directed actions. I will also present ongoing and future work exploring (1) an early-developing gender difference in the tendency to interpret actions as social or physically causal and (2) how infants might learn about actions that have both physical and social functions. Finally, I will discuss the importance of these results for understanding early social learning, a key component of the development of human intelligence.
Room: 46-3310, Cambridge, MA, 02138 United States