Do preverbal infants expect group members to pursue goals by the same inefficient means-actions?

Infants expect agents to act efficiently (Gergely et al., 1996). They also expect individuals belonging to the same group to behave alike (Powell & Spelke, 2012). However, we know little about how
these two tendencies interact. We hypothesize that upon viewing individuals from the same group approaching a goal-object inefficiently, infants could represent this action as a group-specific means-action and expect other group-members (but not agents from a different group) to approach the goal in the same manner despite inefficiency.
Experiment 1 aimed at validating our stimuli as conducive to teleological inferences in 11-month-olds. We showed infants scenes with three “ingroup” agents and one “outgroup” agent based on familiarization events by Powell and Spelke (2012). We also familiarized infants with efficient actions of one ingroup agent detouring a long barrier to obtain the goal. At test the barrier was shorter and didn’t block direct access to the goal, thus rendering the detour-action inefficient. On alternate test-trials
infants watched the familiarization-agent now taking direct path to the goal (efficient trial) or the old detour-path (inefficient trial). Infants looked longer at the inefficient test trials (t (23)= 2.185, p = .04), replicating the previous findings. The procedure for Experiment 2 differed only in that infants were familiarized to inefficient detour-approaches of two ingroup agents and watched actions of a third ingroup agent at test. We predict that if infants represent the inefficient detour as a means-action shared within the group they should look longer at the efficient test trials.