Alan M. Leslie

This chapter examines the innate basis of our concepts of the positive integers. In practice, real valued variables are never exactly equal; nor is it easy to specify an algorithm for establishing exact equality between two random Gaussian variables. Furthermore, because number concepts must support arithmetic inference, a necessary part of the psychological foundations is the integer concept ONE. ONE is required because it is the multiplicative identity element for which no other value, approximate or exact, can be substituted. Moreover, ONE is required by the successor function, which generates all the other positive integers. It is argued that an essential constraint on any proposal for discrete (integer-valued rather than real-valued) mental symbols is computational compatibility with the real- (or rational-) valued mental magnitudes that represent continuous quantity. These constraints rule out most current proposals that postulate systems of discrete numerons or other symbols representing only very small numbers. Alternative proposals are considered.

Kühberger et al. show that producing the Langer effect is considerably more difficult than has been assumed. Although their results clearly demonstrate a need for further exploration of the Langer effect, none of their arguments undermines the evidence against simulation theory that we presented in Nichols et al. (1996). In our study the actor subjects did show an effect, but the prediction subjects did not predict it, despite the fact that they were provided with all the details of the actor's situation. Further, we report additional evidence that corroborates our empirical case against simulation theory.

Psychologists and philosophers have recently been exploring whether the mechanisms which underlie the acquisition of ‘theory of mind’ (ToM) are best characterized as cognitive modules or as developing theories. In this paper, we attempt to clarify what a modular account of ToM entails, and why it is an attractive type of explanation. Intuitions and arguments in this debate often turn on the role of develop‐ment: traditional research on ToM focuses on various developmental sequences, whereas cognitive modules are thought to be static and ‘anti‐developmental’. We suggest that this mistaken view relies on an overly limited notion of modularity, and we explore how ToM might be grounded in a cognitive module and yet still afford development. Modules must ‘come on‐line’, and even fully developed modules may still develop internally, based on their constrained input. We make these points concrete by focusing on a recent proposal to capture the development of ToM in a module via parameterization.

Young children’s failures in reasoning about beliefs and desires, and especially about false beliefs, have been much studied. However, there are few accounts of successful belief-desire reasoning in older children or adults. An exception to this is a model in which belief attribution is treated as a process wherein an inhibitory system selects the most likely content for the belief to be attributed from amongst several competing contents [Leslie, A. M., & Polizzi, P. (1998). Developmental Science, 1, 247–254]. We tested this model with an ‘avoidance false belief task’ in which subjects predict the behavior of a character, who wants to avoid an object but who is mistaken about which of three locations it is in. The task has two equally correct answers—in seeking to avoid the location where she mistakenly believes the object to be, the character might equally go to the location where the object actually is, or to the remaining empty location. However, the model predicts that subjects will prefer one of these answers, selecting the object’s actual location over the empty location. This bias was confirmed in a series of five experiments with children aged between 4 and 8 years of age. A sixth experiment ruled out two rival explanations for children’s biased responding. Two further experiments found the opposite bias in adults. These findings support one selection model as an account of belief-desire reasoning in children, and suggest that a different model is needed for adults. The process of selecting contents for mental state attributions shows a developmental shift between 8 years of age and adulthood.

The ability to engage in and recognize pretend play begins around 18 months. A major challenge for theories of pretense is explaining how children are able to engage in pretense, and how they are able to recognize pretense in others. According to one major account, the metarepresentational theory, young children possess both production and recognition abilities because they possess the mental state concept, PRETEND. According to a more recent rival account, the Behavioral theory, young children are behaviorists about pretense, and only produce and recognize pretense as a sort of behavior--namely, behaving 'as-if'. We review both the metarepresentational and Behavioral accounts and argue that the Behavioral theory fails to characterize very young children's abilities to produce and to recognize pretense. Among other problems, the Behavioral theory implies that children should frequently mis-recognize regular behavior as pretense, while certain regular forms of pretend play should neither be produced nor recognized. Like other mental states, pretense eludes purely behavioral description. The metarepresentational theory does not suffer these problems and provides a better account of children's pretense. 2016 APA, all rights reserved)

Various theories of moral cognition posit that moral intuitions can be understood as the output of a computational process performed over structured mental representations of human action. We propose that action plan diagrams—“act trees”—can be a useful tool for theorists to succinctly and clearly present their hypotheses about the information contained in these representations. We then develop a methodology for using a series of linguistic probes to test the theories embodied in the act trees. In Study 1, we validate the method by testing a specific hypothesis (diagrammed by act trees) about how subjects are representing two classic moral dilemmas and finding that the data support the hypothesis. In Studies 2–4, we explore possible explanations for discrete and surprising findings that our hypothesis did not predict. In Study 5, we apply the method to a less well‐studied case and show how new experiments generated by our method can be used to settle debates about how actions are mentally represented. In Study 6, we argue that our method captures the mental representation of human action better than an alternative approach. A brief conclusion suggests that act trees can be profitably used in various fields interested in complex representations of human action, including law, philosophy, psychology, linguistics, neuroscience, computer science, robotics, and artificial intelligence.

Human social intelligence comprises a wide range of complex cognitive and affective processes that appear to be selectively impaired in autistic spectrum disorders. The study of these neuro- developmental disorders and the study of canonical social intelligence have advanced rapidly over the last twenty years by investigating the two together. Specifically, studies of autism have provided important insights into the nature of ‘theory of mind’ abilities, their normal development and underlying neural systems. At the same time, the idea of impaired development of the neurocognitive mechanisms underlying ‘theory of mind’ has shed new light on the nature of autistic disorders. This general approach is not restricted to the study of impairments but extends to mapping areas of social intelligence that are spared in autism. Here we investigate basic moral judgment and find that it appears to be substantially intact in children with autism who are severely impaired in ‘theory of mind’. At the same time, we extend studies of moral reasoning in normal development by way of a new control task, the ‘cry baby’ task. Cry baby scenarios, in which the distress of the victim is ‘unreasonable’ or ‘unjustified,’ do not elicit moral condemnation from normally developing preschoolers or from children with autism. Judgments of moral transgressions in which the victim displays distress are therefore not likely the result of a simple automatic reaction to the distress and more likely involve moral reasoning. Mapping the cognitive co-morbidity patterns of disordered development should encompass both impairments and sparings because both will be needed to make sense of the neural and genetic levels.

The concept of acting intentionally is an important nexus where ‘theory of mind’ and moral judgment meet. Preschool children’s judgments of intentional action show a valence-driven asymmetry. Children say that a foreseen but disavowed side-effect is brought about 'on purpose' when the side-effect itself is morally bad but not when it is morally good. This is the first demonstration in preschoolers that moral judgment influences judgments of ‘on-purpose’ (as opposed to purpose influencing moral judgment). Judgments of intentional action are usually assumed to be purely factual. That these judgments are sometimes partly normative — even in preschoolers — challenges current understanding. Young children’s judgments regarding foreseen side-effects depend upon whether the children process the idea that the character does not care about the side-effect. As soon as preschoolers effectively process the ‘theory of mind’ concept, NOT CARE THAT P, children show the side-effect effect.idea..

Recent studies reveal spontaneous implicit false-belief understanding in infancy. But is this early ability genuine theory-of-mind? Spontaneous tasks may allow early success by eliminating the selection-response bias thought to underlie later failure on standard tasks. However, using anticipatory eye gaze, we find the same bias in non-verbal tasks in both preschoolers and adults. We argue that the bias arises from theory-of-mind competence itself and takes the form of a rational prior to attribute one's own belief to others. Our discussion then draws attention to a number of other inferential hallmarks of early belief-desire reasoning that together suggest it is the real deal.

Kühberger et al. show that producing the Langer effect is considerably more difficult than has been assumed. Although their results clearly demonstrate a need for further exploration of the Langer effect, none of their arguments undermines the evidence against simulation theory that we presented in Nichols et al. (1996). In our study the actor subjects did show an effect, but the prediction subjects did not predict it, despite the fact that they were provided with all the details of the actor's situation. Further, we report additional evidence that corroborates our empirical case against simulation theory.

Psychologists and philosophers have recently been exploring whether the mechanisms which underlie the acquisition of ‘theory of mind’ (ToM) are best charac- terized as cognitive modules or as developing theories. In this paper, we attempt to clarify what a modular account of ToM entails, and why it is an attractive type of explanation. Intuitions and arguments in this debate often turn on the role of develop- ment: traditional research on ToM focuses on various developmental sequences, whereas cognitive modules are thought to be static and ‘anti-developmental’. We suggest that this mistaken view relies on an overly limited notion of modularity, and we explore how ToM might be grounded in a cognitive module and yet still afford development. Modules must ‘come on-line’, and even fully developed modules may still develop internally, based on their constrained input. We make these points con- crete by focusing on a recent proposal to capture the development of ToM in a module via parameterization.

We use a new model of metarepresentational development to predict a cognitive deficit which could explain a crucial component of the social impairment in childhood autism. One of the manifestations of a basic metarepresentational capacity is a ‘ theory of mind ’. We have reason to believe that autistic children lack such a ‘ theory ’. If this were so, then they would be unable to impute beliefs to others and to predict their behaviour. This hypothesis was tested using Wimmer and Perner’s puppet play paradigm. Normal children and those with Down’s syndrome were used as controls for a group of autistic children. Even though the mental age of the autistic children was higher than that of the controls, they alone failed to impute beliefs to others. Thus the dysfunction we have postulated and demonstrated is independent of mental retardation and specific to autism.

Do victims’ emotions underlie preschoolers’ moral judgment abilities? Study 1 asked preschoolers (n = 72) to judge actions directed at characters who could and could not feel hurt and who did and did not cry. These judgments took into account only the nature of the action, not the nature of the victim. To further investigate how victims’ emotions might impact children’s moral judgments, Study 2 presented preschoolers (n = 37) with stories that varied in transgression type (Moral, Conventional, or None) and victim’s reaction (Crying Present or Crying Absent). As in Study 1, children’s judgments were affected primarily by transgression type, and not by emotion. In an analogous task, judgments of children with autism spectrum disorders (Study 3; n = 12) were affected by both transgression type and crying. Typically developing children’s moral judgments are thus concerned primarily with action type, not with emotional displays, but the judgments of children with autism spectrum disorders can be swayed by victims’ emotions

Number concepts must support arithmetic inference. Using this principle, it can be argued that the integer concept of exactly ONE is a necessary part of the psychological foundations of number, as is the notion of the exact equality - that is, perfect substitutability. The inability to support reasoning involving exact equality is a shortcoming in current theories about the development of numerical reasoning. A simple innate basis for the natural number concepts can be proposed that embodies the arithmetic principle, supports exact equality and also enables computational compatibility with real- or rational-valued mental magnitudes