Taking the intentional stance at 12 months of age

This paper reports a habituation study indicating that 12-month-old infants can take the "intentional stance" in interpreting the goal-directed spatial behavior of a rational agent. First, we examine previous empirical claims suggesting that the ability to attribute intentions to others emerges during the second half of the first year. It is argued that neither the perceptual evidence (concerning the early ability to discriminate agents), nor the behavioral data (indicating the use of communicative gestures for instrumental purposes) are sufficient to support such claims about the early appearance of a theory of mind, as there are alternative explanations for these phenomena in terms of simpler psychological processes. It is then suggested that to show that an infant indeed attributes an intention to interpret the goal-directed behavior of a rational agent, one needs to demonstrate that the baby can generate an expectation about the most rational future means action that the agent will perform in a new situation to achieve its goal. We then describe a visual habituation study that meets this requirement. The results demonstrate that based on the equifinal structure of an agent's spatial behavior, 12-month-old infants can identify the agent's goal and interpret its actions causally in relation to it. Furthermore, our study indicates that infants of this age are able to evaluate the rationality of the agent's goal-directed actions, which is a necessary requirement for applying the intentional stance. In closing, we discuss some of the theoretical and methodological implications of our study.