Infants understand deceptive intentions to implant false beliefs about identity: New evidence for early mentalistic reasoning

Abstract

Are infants capable of representing false beliefs, as the mentalistic account of early psychological reasoning suggests, or are they incapable of doing so, as the minimalist account suggests? The present research sought to shed light on this debate by testing the minimalist claim that a signature limit of early psychological reasoning is a specific inability to understand false beliefs about identity: because of their limited representational capabilities, infants should be unable to make sense of situations where an agent mistakes one object for another, visually identical object. To evaluate this claim, three experiments examined whether 17-month-olds could reason about the actions of a deceptive agent who sought to implant in another agent a false belief about the identity of an object. In each experiment, a thief attempted to secretly steal a desirable rattling toy during its owner’s absence by substituting a less desirable silent toy. Infants realized that this substitution could be effective only if the silent toy was visually identical to the rattling toy (Experiment 1) and the owner did not routinely shake her toy when she returned (Experiment 2). When these conditions were met, infants expected the owner to be deceived and to mistake the silent toy for the rattling toy she had left behind (Experiment 3). Together, these results cast doubt on the minimalist claim that infants cannot represent false beliefs about identity. More generally, these results indicate that infants in the 2nd year of life can reason not only about the actions of agents who hold false beliefs, but also about the actions of agents who seek to implant false beliefs, thus providing new support for the mentalistic claim that an abstract capacity to reason about false beliefs emerges early in human development.

Surprise! 20-month-old infants understand the emotional consequences of false beliefs

“…First, they confirm prior findings that by the second year of life, infants can attribute false beliefs to agents (e.g., Buttelmann et al, 2009;Kovács et al, 2010;Luo, 2011;Onishi & Baillargeon, 2005;Scott et al, 2015;Senju et al, 2011;Träuble et al, 2010). Second, these results extend these findings to a novel belief-based response: infants can reason not only about which location a mistaken agent will act on, but also about how her false belief will affect her subsequent emotional displays.…”

“…Rather, the present study adds to a growing body of evidence that infants can reason about causal interactions amongst mental states (e.g., Scott & Baillargeon, 2009;Scott et al, 2015). As such evidence accumulates, the existence of arbitrary limits on infants' false-belief understanding become less plausible.…”

“…By tracking where the agent last registered the object, the early-developing system can predict that the agent will reach for the object in its original location. The early-developing system is thus able to explain the results of many prior false-belief tasks with infants (for exceptions, see Scott et al, 2015).…”

Two-and-a-half-year-olds succeed at a traditional false-belief task with reduced processing demands

“…By the same token, our results also cast doubt on the view that a fundamental change in children's false-belief understanding takes place around age 4 y and makes possible success at these tasks. When processing demands are sufficiently reduced, even 2.5-y-olds succeed at a traditional task, suggesting that a single psychological-reasoning system, capable of attributing counterfactual states as well as motivational and epistemic states, exists from infancy onward (1,31,52,53).…”

The Developmental Origins of False-Belief Understanding

“…Since 2005, over two dozen published studies have reported evidence of falsebelief understanding in children between 6 months and 3 years of age (for a review, see Baillargeon et al, 2015). These subsequent studies have addressed two important, interrelated questions regarding the origins and development of false-belief understanding.…”