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

Abstract

Recent studies suggest that by the second year of life, infants can attribute false beliefs to agents.However, prior studies have largely focused on infants' ability to predict a mistaken agent's physical actions on objects. The present research investigated whether 20-month-old infants could also reason about belief-based emotional displays. In Experiments 1 and 2, infants viewed an agent who shook two objects: one rattled and the other was silent. Infants expected the agent to express surprise at the silent object if she had a false belief that both objects rattled, but not if she was merely ignorant about the objects' properties. Experiment 3 replicated and extended these findings: if an agent falsely believed that two containers held toy bears (when only one did so), infants expected the agent to express surprise at the empty, but not the full, container.Together, these results provide the first evidence that infants in the second year of life understand the causal relationship between beliefs and emotional displays. These findings thus provide new evidence for false-belief understanding in infancy and suggest that infants, like older children, possess a robust understanding of belief that applies to a broad range of belief-based responses.

Early False-Belief Understanding

“…Focusing first on behavioral responses, when an agent holds a false belief about a scene, infants age 7 months and older have been found to look significantly longer when the agent acts in a manner that is inconsistent, as opposed to consistent, with this belief (violation-ofexpectation tasks) [9,[11][12][13][14][15][16][17][18][19][20][21][22][23][24]. When an agent falsely believes that a desired object is in location-A, infants age 17 months and older visually anticipate that the agent will approach location-A (anticipatory-looking tasks) [25][26][27][28][29][30][31][32], and infants age 18 months and older spontaneously point to inform the agent that the object has been moved to another location or has been replaced with an aversive object (anticipatory-pointing tasks) [33][34].…”

“…Nontraditional tasks have produced evidence that infants and toddlers can reason about a wide range of behaviors by agents with false beliefs. These behaviors include: (a) physical actions, such as where a mistaken agent will search for a desired object or which object she will select to produce a desired effect [9,18]; (b) social interactions, such as whether a mistaken agent will continue to interact positively with another agent [12]; (c) verbal statements, such as which object a mistaken agent intends to label or request [42][43]; and (d) emotional responses, such as how an agent will react upon discovering she was mistaken [16]. In this last task, 20-month-olds first watched an agent play with two rattling toys.…”

Do infants understand false beliefs? We don’t know yet – A commentary on Baillargeon, Buttelmann and Southgate’s commentary

“…However, the length of our outcome phase was not a randomly chosen time interval, but based on literature review. That is, in most relevant VoE studies, looking time measurement starts after the actor remains still, and children then typically watch incongruent test trials for 15 to 25 seconds (or even longer, up to about 50 seconds) before they look away for two consecutive seconds (e.g., Scott, 2017;Scott, Richman, & Baillargeon, 2015;Surian, Caldi, & Sperber, 2007;Woodward, 1998). Therefore, we chose an adequate but moderate still phase length of 20 seconds, assuming to get neither ceiling nor floor effects in cumulative looking time (which we did not get).…”

Infants attribute false beliefs to a toy crane

“…This striking finding led to the conclusion that ‘infants already attribute false beliefs to agents, calling into question the conclusion that false‐belief understanding is not achieved until about 4 years of age’ (page 238) and that ‘false‐belief understanding emerges early in life and is robust and sophisticated ’ (Scott & Baillargeon, , page 246). This mentalistic account posits that this ability is masked by the high task demands of the standard false belief task, which requires well‐developed executive functioning abilities and verbal skills (Baillargeon, Scott, & He, ; Scott, ). Over the past decade, a large number of experiments have replicated and extended the original findings using a range of procedures all based on spontaneous responses, including anticipatory looking and prompted helping (see Scott & Baillargeon, for a review).…”