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

Expecting the Unexpected: Infants Use Others' Surprise to Revise Their Own Expectations

Human infants show systematic responses to events that violate their expectations. Can they also revise these expectations based on others' expressions of surprise? Here we ask whether infants (N = 156, mean = 15.2 months, range: 12.0-18.0 months) can use an experimenter's expression of surprise to revise their own expectations about statistically probable vs. improbable events. An experimenter sampled a ball from a box of red and white balls and briefly displayed either a surprised or an unsurprised expression at the outcome before revealing it to the infant. Following an unsurprised expression, the results were consistent with prior work; infants looked longer at a statistically improbable outcome than a probable outcome. Following a surprised expression, however, this standard pattern disappeared or was even reversed. These results suggest that even before infants can observe the unexpected events themselves, they can use others' surprise to expect the unexpected. Starting early in life, human learners can leverage social information that signals others' prediction error to update their own predictions.

Calculated Feelings: How Children Use Probability to Infer Emotions

Developing the ability to accurately infer others' emotions is crucial for children's cognitive development. Here, we offer a new theoretical perspective on how children develop this ability. We first review recent work showing that with age, children increasingly use probability to infer emotions. We discuss how these findings do not fit with prominent accounts of how children understand emotions, namely the script account and the theory of mind account. We then outline a theory of how probability allows children to infer others' emotions. Specifically, we suggest that probability provides children with information about how much weight to put on alternative outcomes, allowing them to infer emotions by comparing outcomes to counterfactual alternatives.

The influence of language input on 3-year-olds' learning about novel social categories

There is considerable variability in the social categories that children essentialize and the types of expectations children form about these categories, suggesting children's essentialist beliefs are shaped by environmental input. Prior studies have shown that exposure to generic statements about a social category promotes essentialist beliefs in 4.5- to 8-year-old children. However, by this age children form essentialist beliefs quite robustly, and thus it is unclear whether generic statements impact children's expectations about social categories at younger ages when essentialist beliefs first begin to emerge. Moreover, in prior studies the generic statements were delivered by an experimenter and carefully controlled, and thus it is unclear whether these statements would have the same impact if they occurred in a somewhat less constrained setting, such as parents reading a picture book to their child. The current study addressed these open questions by investigating whether generic statements delivered during a picture-book interaction with their parents influenced 3-year-olds' expectations about members of a novel social category. Our results showed that children who heard generic statements during the picture-book interaction used social-group membership to make inferences about the likely behavior of a novel category member, whereas children who were not exposed to generic statements did not. These findings suggest that as early as 3 years of age, children's expectations about social categories are influenced by generic statements that occur during brief parent-child interactions.

Financial concern reduces child directed speech in a socioeconomically diverse sample

Socioeconomic status predicts the quantity and nature of child-directed speech that parents produce. However, the mechanisms underlying this relationship remain unclear. This study investigated whether the cognitive load imposed by resource scarcity suppresses parent talk by examining time-dependent variation in child-directed speech in a socioeconomically diverse sample. We predicted that child-directed speech would be lowest at the end of the month when Americans report the greatest financial strain. 166 parents and their 2.5 to 3-year-old children (80 female) participated in a picture-book activity; the number of utterances, word tokens, and word types used by parents were calculated. All three parent language measures were negatively correlated with the date of the month the activity took place, and this relationship did not vary with parental education. These findings suggest that above and beyond individual properties of parents, contextual factors such as financial concerns exert influence on how parents interact with their children.

Pretending emotions in the early years: The role of language and symbolic play

Although 3-year-old children sometimes simulate emotions to adapt to social norms, we do not know if even younger children can pretend emotions in playful contexts. The present study investigated (1) what emotions infants of 1-2 years old are capable of pretending and (2) the possible role of language and symbolic play in the ability to pretend emotions. The sample included 69 infants aged 18 to 31 months and their parents. Infants were administrated the Test of Pretend Play, and their parents responded to the MacArthur-Bates CDI-II inventory, part of the MacArthur-Bates CDI-I, and a questionnaire about the expression of pretend emotions. Results suggest that very young children simulate emotions. Furthermore, children's simulation of emotions was related to both symbolic play and language. Specifically, the ability to label emotions was linked to the ability to simulate them. The role of language and symbolic play in the development of the capacity to express and understand pretend emotions is discussed.

Factors Facilitating Early Emotion Understanding Development: Contributions to Individual Differences

Children's emotion understanding is crucial for healthy social and academic development. The behaviors influenced by emotion understanding in childhood have received much attention, but less focus has been placed on factors that may predict individual differences in emotion understanding, the principle issue addressed in the current review. A more thorough understanding of the developmental underpinnings of this skill may allow for better prediction of emotion understanding, and for interventions to improve emotion understanding early in development. Here, we present theoretical arguments for the substantial roles of three aspects of children's environments in development of emotion understanding: family expressiveness, discussions about emotions, and language development, and we discuss how these are interrelated. Ultimately, this may aid in predicting the effects of environmental influences on development of emotion understanding more broadly, and the mechanisms by which they do so.

Understanding Pretend Emotions in Children Who Are Deaf and Hard of Hearing

Children who are deaf and hard of hearing (DHH) and born to hearing parents have delays in their social-cognitive development and in particular in their theory of mind (ToM). These delays are often attributed to the difficulties they encounter in acquiring age-appropriate linguistic and communicative skills. The present study asks whether this developmental delay extends to problems with understanding pretend emotions and if linguistic difficulties are related to this area. A total of 173 children (82 DHH and 91 hearing) between 3 and 8 years of age received a set of emotion and language measures. Results showed that children who are DHH were delayed in understanding pretend emotions, and this was strongly related to their difficulties with expressive vocabulary and pragmatics. In summary, children who are DHH and have experienced reduced access to language and communicative interaction have a restricted understanding of the communicative intentions of emotional expressions. These delays may have implications for their social relationships with surrounding family and other children.

Infants attribute false beliefs to a toy crane

The mentalistic view of early theory of mind posits that infants possess a robust and sophisticated understanding of false belief that is masked by the demands of traditional explicit tasks. Much of the evidence supporting this mentalistic view comes from infants' looking time at events that violate their expectations about the beliefs of a human agent. We conducted a replication of the violation-of-expectation procedure, except that the human agent was replaced by an inanimate agent. Infants watched a toy crane repeatedly move toward a box containing an object. In the absence of the crane, the object changed location. When the crane returned, 16-month-old infants looked longer when it turned toward the object's new location, consistent with the attribution of a false belief to the crane. These results suggest that infants spontaneously attribute false beliefs to inanimate agents. A video abstract of this article can be viewed at https://youtu.be/qqEPPhd9FDo.

Do Infants in the First Year of Life Expect Equal Resource Allocations?

Recent research has provided converging evidence, using multiple tasks, of sensitivity to fairness in the second year of life. In contrast, findings in the first year have been mixed, leaving it unclear whether young infants possess an expectation of fairness. The present research examined the possibility that young infants might expect windfall resources to be divided equally between similar recipients, but might demonstrate this expectation only under very simple conditions. In three violation-of-expectation experiments, 9-month-olds (N = 120) expected an experimenter to divide two cookies equally between two animated puppets (1:1), and they detected a violation when she divided them unfairly instead (2:0). The same positive result was obtained whether the experimenter gave the cookies one by one to the puppets (Experiments 1–2) or first separated them onto placemats and then gave each puppet a placemat (Experiment 3). However, a negative result was obtained when four (as opposed to two) cookies were allocated: Infants looked about equally whether they saw a fair (2:2) or an unfair (3:1) distribution (Experiment 3). A final experiment revealed that 4-month-olds (N = 40) also expected an experimenter to distribute two cookies equally between two animated puppets (Experiment 4). Together, these and various control results support two broad conclusions. First, sensitivity to fairness emerges very early in life, consistent with claims that an abstract expectation of fairness is part of the basic structure of human moral cognition. Second, this expectation can at first be observed only under simple conditions, and speculations are offered as to why this might be the case.

The Developmental Origins of False-Belief Understanding

Understanding that individuals can be mistaken, or hold false beliefs, about the world is an important human ability that plays a vital role in social interactions. When and how does this ability develop? Traditional investigations using elicited-response tasks suggested that false-belief understanding did not emerge until at least age 4. However, more recent studies have shown that children demonstrate false-belief understanding much earlier when tested via other means. In the present article, I summarize recent evidence that a robust, flexible understanding of false belief emerges in infancy and discuss why older children fail elicited-response tasks despite their ability to represent beliefs.