Infants are sensitive to the social signaling value of shared inefficient behaviors.

Actions that are blatantly inefficient to achieve non-social goals are often used to convey information about agents' social affiliation, as in the case of rituals. We argue that when reproduced, actions that are individually inefficient acquire a social signaling value owing to the mechanisms that support humans' intuitive analysis of actions. We tested our hypothesis on 15-month-old infants who were familiarized with an agent that reproduced or merely observed the actions of efficient and inefficient individuals.

Infants' representation of asymmetric social influence.

In social groups, some individuals have more influence than others, for example, because they are learned from or because they coordinate collective actions. Identifying these influential individuals is crucial to learn about one's social environment. Here, we tested whether infants represent asymmetric social influence among individuals from observing the imitation of movements in the absence of any observable coercion or order.

Small groups lead, big groups control: Perceptions of numerical group size, power, and status across development.

Participants (N = 384 three- to ten-year-olds; 51% girls, 49% boys; 73% White, 18% multiracial/other, 5% Asian, and 3% Black; N = 610 adults) saw depictions of 20 individuals split into two social groups (1:19; 2:18; 5:15; or 8:12 per group) and selected which group was "in charge" (Experiment 1), "the leader" (Experiment 2), or likely to "get the stuff" (resources) in a conflict (Experiment 3). Whereas participants across ages predicted the larger group would "get the stuff," a tendency to view smaller groups as "in charge" and "the leader" strengthened with age and when the smaller group was rarer. These findings suggest the perceived relation between numerical group size and hierarchy is flexible and inform theory regarding the developmental trajectories of reasoning about power and status.

Infants' representation of social hierarchies in absence of physical dominance.

Social hierarchies are ubiquitous in all human relations since birth, but little is known about how they emerge during infancy. Previous studies have shown that infants can represent hierarchical relationships when they arise from the physical superiority of one agent over the other, but humans have the capacity to allocate social status in others through cues that not necessary entail agents' physical formidability. Here we investigate infants' capacity to recognize the social status of different agents when there are no observable cues of physical dominance.

Efficiency as a principle for social preferences in infancy.

Two separate research lines have shown that (1) infants expect agents to move efficiently toward goal states and that (2) infants navigate the social world selectively, preferring some individuals to others and attributing social preferences to others' agents. Here, we studied how the expectation of efficient actions influences infants' looking preferences and their inferences about others' preferences. We presented 15-month-olds with a set of videos containing three geometric figures depicting social agents.

Speak My Language and I Will Remember Your Face Better: An ERP Study.

Here we investigated how the language in which a person addresses us, native or foreign, influences subsequent face recognition. In an old/new paradigm, we explored the behavioral and electrophysiological activity associated with face recognition memory. Participants were first presented with faces accompanied by voices speaking either in their native (NL) or foreign language (FL).