Not so innocent: Reasoning about costs, competence, and culpability in very early childhood

Not so innocent: Reasoning about costs, competence, and culpability in very early childhood Julian Jara-Ettinger (jjara@mit.edu) Joshua B. Tenenbaum (jbt@mit.edu) Laura E. Schulz (lschulz@mit.edu) Department of Brain and Cognitive Sciences, MIT Cambridge, MA 02139 USA Abstract 2003 for review). Consistent with a large body of prior work, we assume that inferences about agents’ goal-directed actions are governed by a principle of rational expectation: the idea that agents act efficiently to achieve their goals (e.g., Scott & Baillargeon, 2013; Gergely & Csibra, 2003). Computational work on the principle of rational expectation as probabilistic inference over rational planning has been used to successfully model adults’ reasoning about agents’ goals (Baker, Saxe, & Tenenbaum, 2009, 2011; Ullman et al., 2010; Jara-Ettinger, Baker, & Tenenbaum, 2012). Social evaluations depend on our ability to interpret other peo- ple’s behavior. In adults, these evaluations are influenced by our perception of the competence and motivation of the agent: helping when it is difficult to help is praiseworthy; not help- ing when it is easy to help is reprehensible. Here we look at young children’s capacity to make competence attributions and its relation to their social evaluations. We find that as early as 18-months, infants can use the time and effort associated with achieving a goal-directed action to distinguish agents, and that infants prefer more competent agents. When asked to choose between two agents who act as moral bystanders and refuse to engage in a helpful action, we find a sustained preference for the more competent agent until the age of three, when the preference is reversed. We argue that the ability to calculate the cost and benefits of goal-directed action originates in early childhood and plays a fundamental role in moral reasoning. Keywords: Action Understanding; Morality; Social Cogni- tion; Theory of Mind. The principle of rational expectation is predicated on the understanding that agents act in ways that will minimize costs and maximize rewards. We propose that the ability to com- pute the costs and benefits of actions forms the heart of a na¨ive utility calculus that supports inference at the earliest stages of children’s theories of agency. (See Jara-Ettinger, Gweon, Tenenbaum, & Schulz in prep, for a detailed version of this argument and experimental studies in childhood). Here we provide an informal description of this approach and test one of its qualitative predictions: that an analysis of the cost functions associated with agent actions is central to the moral judgments even of very young children. Introduction The past decade has seen a revolution in our understand- ing of psychosocial reasoning in early childhood. Recent findings suggest that infants infer the false beliefs of oth- ers (Onishi & Baillargeon, 2005; Southgate, Senju, & Csi- bra, 2007; Kov´acs, T´egl´as, & Endress, 2010), distinguish helpers, hinderers, and moral bystanders (Kuhlmeier, Wynn, & Bloom, 2003; Hamlin, Wynn, & Bloom, 2007); draw dif- ferent inferences about actions directed towards member of in-groups and out-groups (Baillargeon et al., in press); pre- dict actions based on social dominance (Thomsen, Franken- huis, Ingold-Smith, & Carey, 2011), judge third party agents transitively, based on how they interact with moral transgres- sors (Hamlin, Wynn, Bloom, & Mahajan, 2011; Sloane, Bail- largeon, & Premack, 2012); and consider agents’ knowledge about a target agent’s preferences in making moral judgments (Hamlin, Ullman, Tenenbaum, Goodman, & Baker, 2013). The discovery of infants’ sophisticated social intelligence is among the most exciting recent developments in the field of cognitive science. However, to date relatively little is under- stood about the types of computations that underlie these so- cial judgments. Intuitively, adult social evaluations are influenced by our perception of how much an action will cost the agent who performs it. Imagine for instance, that your neighbor, Sally, watches a child struggle to reach a package on the top shelf of a grocery store. Sally stands by and does nothing at all. Although there is no intrinsic relationship between height and moral worth, you may well judge Sally less harshly if she is 4’11” than if she is an NCAA Division 1 basketball player. What analysis underlies this inference? We suggest that in evaluating and predicting agents’ actions, observers auto- matically compute the cost of actions. The perceived cost of an action (controlling for constraints imposed by the environ- ment) reflects inferences about the agents’ level of compe- tence; the perceived benefits of the action to the agent reflect inferences about the agents’ level of motivation. Motivation and competence jointly affect the probability of the agents’ actions so the two attributions trade-off with each other. If we know that an agent is highly motivated and she fails to act, we may infer that she is incompetent; conversely, if we know the agent is highly competent and she fails to act, we may infer that she is unmotivated. Morally, lack of compe- tence to help is an exonerating factor; lack of motivation is not. Rational Planning, Social Evaluations, and a Na¨ive Utility Calculus Here we propose a new approach to thinking about social rea- soning in infancy, drawing on the insight that the ability to reason about goal-directed action is at the core of our cog- nition about agents. (See Carey, 2009; Gergely & Csibra,