An important aspect of a child’s cognitive development is the emergence of a theory of mind, or the ability to understand that others can have beliefs, knowledge and desires that are different from one’s own. Previously, it was believed that children showed this ability around the age of 3 to 4 by using a verbal task to tap into their understanding of other people’s mental states. More recent studies have looked at infants’ understanding of theory of mind by using non-verbal measures, such as the True-Belief Task. In a True-Belief Task, the child’s reaction to where an agent searches for an object is recorded when the agent has witnessed where the object was last hidden. As children and infants tend to look longer at unexpected or surprising situations, their reactions to an event, such as in a True Belief Task, can help researchers understand whether the contents of what the infants sees is consistent with the infants’ perception and expectations for other people’s behavior; thus implicitly tapping into their understanding of theory of mind. To further examine infants’ understanding of theory of mind, a study was conducted at Concordia Unversity looking at whether the reliability or trustworthiness of an agent’s gaze has an effect on infants’ reasoning about the agent’s beliefs.
In this study forty-nine 16 month old infants completed a Search Task followed by a True-Belief Task. The purpose of the Search Task was was to establish the reliability of the “looker” or the experimenter. This was accomplished by having the infant observe the experimenter as she opened a container and looked inside while expressing happiness verbally and expressively. The experimenter then passed the container to the infant to explore the container; thus allowing the infant to see what the experimenter was looking at. Approximately half of the participating infants were placed in the ‘reliable looker’ condition and would discover a toy inside the container upon inspection. In this condition, the emotional expression of the experimenter was consistent with what she was looking at. The remaining infants were placed in the ‘unreliable looker’ condition and would discover an empty container upon inspection. In this latter condition, the emotional expression of the experimenter was inconsistent with what she was looking at.
Just as in previous studies using this task, infants in the “unreliable looker” group took longer to begin examining the container on the last trial than they did on the first trial whereas infants in the “reliable group” showed no differences. These findings suggest that infants in the “unreliable group” showed a lack of interest in an empty container because they associated the looker’s emotional expression with a lack of content.