Josef Perner

Beliefs about beliefs: Representation and constraining function of wrong beliefs in young children's understanding of deception

‘A travelling salesman found himself spending the night at home with his wife when one of his trips was unexpectedly cancelled. The two of them were sound asleep, when in the middle of the night there was a loud knock at the front door. The wife woke up with a start and cried out, ‘Oh, my God! It’s my husband!* Whereupon the husband leapt out from the bed, ran across the room and jumped out the window.’ Schank and Abelson, 1977, p. 59.

John Thinks That Mary Thinks That - Attribution of 2nd-Order Beliefs by 5-Year-Old to 10-Year-Old Children

Abstract Understanding of second-order belief structures by 5- and 10-year-old children was assessed in acted stories in which two characters (John and Mary) were independently informed about an objects (ice-cream vans) unexpected transfer to a new location. Hence both John and Mary knew where the van was but there was a mistake in Johns second-order belief about Marys belief: “John thinks Mary thinks the van is still at the old place”. Childrens understanding of this second-order belief was tested by asking “Where does John think Mary will go for ice cream?” Correct answers could only be given if Johns second-order belief was represented, since all shortcut reasoning based on first-order beliefs would have led to the wrong answer. Results suggested unexpected early competence around the age of 6 and 7 years, shown under optimal conditions when inference of second-order beliefs was prompted.

Exploration of the autistic child's theory of mind: knowledge, Belief, and communication

26 autistic children with mental ages of 3-13 years were tested on 3 tasks that are within the capability of 3- or 4-year-old normal children. The first task tested understanding of a mistaken belief. Children were shown a typical box of a certain brand of sweets, and they all thought that it contained that kind of sweet. To their surprise, however, the box contained something else. Yet, only 4 out of the 26 autistic children were able to anticipate that another child in the same situation would make the same mistake. In contrast, all but 1 of 12 children with specific language impairment, matched for mental age, understood that others would be as misled as they had been themselves. The autistic children were also tested for their ability to infer knowledge about the content of a container from having or not having looked inside. All 4 children who had passed the belief task and an additional 4 performed perfectly, but most failed. The third task assessed childrens pragmatic ability to adjust their answers to provide new rather than repeat old information. Here, too, most autistic children seemed unable to reliably make the correct adjustment. These results confirm the hypothesis that autistic children have profound difficulty in taking account of mental states.

Implicit Understanding of Belief.

Abstract Implicit understanding of false belief was investigated by monitoring where children look in anticipation of a protagonist reappearing, when the protagonist mistakenly thinks that his desired object is in a different place from the place where it really is. This implicit measure of understanding was contrasted with childrens explicit answers to the experimenters question about where the protagonist would look for the object. Children from 2 years 5 months to 2 years 10 months erroneously looked at the objects real location, which they gave for their answer. From 2 years 11 months to 4 years 5 months, about 90% of the children looked at the empty location where the protagonist thought the object was. In sharp contrast, only about 45% of the children in this age span gave that location as their explicit answer to the experimenters question. These results are explained in terms of a distinction between representing a fact and making a judgment about that fact.

A theory of implicit and explicit knowledge

The implicit-explicit distinction is applied to knowledge representations. Knowledge is taken to be an attitude towards a proposition which is true. The proposition itself predicates a property to some entity. A number of ways in which knowledge can be implicit or explicit emerge. If a higher aspect is known explicitly then each lower one must also be known explicitly. This partial hierarchy reduces the number of ways in which knowledge can be explicit. In the most important type of implicit knowledge, representations merely reflect the property of objects or events without predicating them of any particular entity. The clearest cases of explicit knowledge of a fact are representations of ones own attitude of knowing that fact. These distinctions are discussed in their relationship to similar distinctions such as procedural-declarative, conscious-unconscious, verbalizable-nonverbalizable, direct-indirect tests, and automatic-voluntary control. This is followed by an outline of how these distinctions can be used to integrate and relate the often divergent uses of the implicit-explicit distinction in different research areas. We illustrate this for visual perception, memory, cognitive development, and artificial grammar learning.

Fractionating theory of mind: a meta-analysis of functional brain imaging studies.

We meta-analyzed imaging studies on theory of mind and formed individual task groups based on stimuli and instructions. Overlap in brain activation between all task groups was found in the mPFC and in the bilateral posterior TPJ. This supports the idea of a core network for theory of mind that is activated whenever we are reasoning about mental states, irrespective of the task- and stimulus-formats (Mar, 2011). In addition, we found a number of task-related activation differences surrounding this core-network. ROI based analyses show that areas in the TPJ, the mPFC, the precuneus, the temporal lobes and the inferior frontal gyri have distinct profiles of task-related activation. Functional accounts of these areas are reviewed and discussed with respect to our findings.

Children's Understanding of Informational Access as Source of Knowledge.

WIMMER, HEINZ; HOGREFE, G.-JORGEN; and PERNER, JOSEF. Childrens Understanding of Informational Access as Source of Knowledge. CHILD DEVELOPMENT, 1988, 59, 386-396. A sharp improvement was found between 3 years and 5 years in childrens understanding of the role of visual perception and linguistic communication in knowledge formation. Although children at any age were able to obtain knowledge and could reliably introspect on the existence of knowledge obtained through visual and linguistic information, most 3and some 4-year-olds seemed completely ignorant about the causal connection between access to an informational source and resulting knowledge. They could not tell how they themselves had acquired a particular piece of knowledge (i.e., whether they had been shown or told). They were also incapable of assessing another persons knowledge of a fact on the basis of observing that person being deprived of or being given information about that fact.

Theory of Mind and Self-Control: More than a Common Problem of Inhibition

This study tested the theory that advances on theory-of-mind tasks and on executive function tasks show a strong correlation because the typically used theory-of-mind tasks pose the same executive demands. In Experiment 1 with fifty-six 3- to 6-year-old children, performance on the dimensional change card-sorting task as an executive function task was correlated with performance on the usual false-belief prediction task, r = .65, and the false-belief explanation task, r = .65, as measures of theory-of-mind development. Because the explanation version of the false-belief test is supposed to be free of the alleged executive demands inherent in the prediction version, the equally strong correlation with the executive function task suggests that this correlation cannot be due to common executive demands. In Experiment 2, the basic finding of Experiment 1 was replicated on another sample of 73 children, ages 3 to 5.5 years. The need for new theories to explain the developmental link between theory of mind and executive function development is discussed, and some existing candidates are evaluated.

Framing decisions: Hypothetical and real

This paper addresses the general issue of whether the practice of investigating human decision making in hypothetical choice situations is at all warranted, or under what conditions. A particularly relevant factor that affects the match between real decisions and hypothetical decisions is the importance of a decisions consequences. In the literature experimental gambles tend to confound the reality of the decision situation with the size of the payoffs: hypothetical decisions tend to offer large payoffs, and real decisions tend to offer only small payoffs. Using the well-known framing effect (a tendency of risk-aversion for gains and of risk-seeking for losses) we find that the framing effect depends on payoff size but hypothetical choices match real choices for small as well as large payoffs. These results appear paradoxical unless size of incentive is clearly distinguished from the reality status of decision (real versus hypothetical). Since the field lacks a general theory of when hypothetical decisions match real decisions, the discussion presents an outline for developing such a theory. 2002 Elsevier Science (USA). All rights reserved.

How Parenting Style Affects False Belief Understanding

This study investigated whether mothers facilitate false belief understanding, and if so, what strategies are particularly relevant. The mothers of 64 3- and 4-year-olds were given questionnaires eliciting information about mothers education, mothers occupation, number of younger and older siblings, the time the child spends with mother, and about how mothers deal with five disciplinary situations with their child. Three variables were positively correlated with belief understanding: age, number of older siblings, and number of times mothers said they would respond to the disciplinary situations by asking the child to reflect on the victims feelings (How Feel responses). These three variables had an independent effect on belief understanding because each was significant after accounting for the influence due to the other two variables. In contrast, there was no significant positive relation between belief understanding and mothers who engaged their child in general discussion and exploration of the disciplinary issues, or who simply reprimanded the child without discussing the situation. The effects for number of older siblings and How Feel responses remained even after the influence due to the childs age, verbal mental age, time spent with the mother, and number of younger siblings was accounted for. The results are consistent with recent research showing that parent-child relations may be important for theory of mind understanding. More importantly, they provide insight into a specific strategy by which parents may help children learn about mental states.