Theory of Mind

http://host.uniroma3.it/progetti/kant/field/tom.htm

Introduction

Interpreting other people’s actions and intentions involves a mutual ascription of contentful mental states such that the understanding of the social world around us becomes coherent and intelligible. Our everyday understanding of others, our folk psychology, is our most fundamental resource for introducing meanings in a world of causes. Folk psychology as a practice has been a major topic of philosophical and psychological investigation along the overall history of thought. Recently, a new perspective on folk psychology has emerged in philosophy of mind and psychology. According to this perspective, our interpretive abilities should be viewed as a competence, a specific endowment of the human mind specialised to understand others and ourselves in terms of mental states. A new field of investigation, called Theory of Mind, is now emerging as a major issue in cognitive studies.

What is "Theory of Mind"?

A "Theory of Mind" (often abbreviated in TOM) is a specific cognitive ability to understand others as intentional agents, that is, to interpret their minds in terms of theoretical concepts of intentional states such as beliefs and desires. It has been commonplace in philosophy (see Davidson 1984; Dennett 1987) to see this ability as intrinsically dependent upon our linguistic abilities. After all, language provides us a representational medium for meaning and intentionality : thanks to language we are able to describe others people’s and our own actions in an intentional way as in : "Ralph believes that Mary intends him to persuade George that p". According to this view, the intensionality of natural language, that is, its suitability for expressing meanings and thoughts, is the key for understanding the intentionality of our theory of mind.

A major challenge to this view came from studies on primate cognition and comparative psychology. In their 1978 famous paper : "Does the chimpanzee have a theory of mind?" D. Premack and G. Woodruff argued that experimental evidence of chimpanzees’ understanding of human behaviour could be interpreted as detection of intentions. Although Premack and Woodruff experimental data have been challenged by other primatologists (see Tomasello & Call, 1997, ch. 10), there is a growing evidence showing that non human primates have some intentional understanding of their social world (see Byrne & Whiten 1988; Tomasello & Call, 1997). The presence of such a capacity in non human (and obviously non-linguistic) species lead to the conclusion that it was possible to investigate TOM as a biological endowment independently of language.

The "False Belief Task"

A more focused perspective on TOM comes from developmental psychology. Children show a precocious ability to understand intentions and other important aspects of the mind (as gaze direction, attention, pretense). Nevertheless, in the early 80, the psychologists H. Wimmer and J. Perner showed that a full-fledged TOM doesn’t develop before the age of 3/4. They set up a series of experimental tests in order to check whether children between 3 and 5 years of age were able to attribute a false belief to someone else. In one of these experiments, children see a scene in which a character, Maxi, puts chocolate in a drawer and goes away. While he is away, his mother takes a bit of chocolate for cooking and then puts it somewhere else and goes out. Then Maxi comes back, and the experimenter asks: "Where will Maxi look for the chocolate?". The 1983 original results showed that children over 5 did not have problems in attributing to Maxi a false belief, whereas younger child ren predicted indifferently that Maxi could look for the chocolate where his mother has put it. Further experiments lowered the threshold of attributing false beliefs to 3/4 years of age. The false belief task , as it is called, defines a sharp watershed between a stage of child’s development in which children have a sort of "transparent" reading of mind and reality (people believe what it is the case), and a stage in which they show a capacity of having an "opaque" reading of mind and reality, that is, they can easily distinguish between what is the case and what people believe is the case. This has been taken as an important piece of evidence of the development of a domain specific ability in dealing with mentalistic concepts, such as believe, which doesn’t seem to be available in earlier stages.


Which format for TOM?

Although there is general consensus that TOM is a domain specific theory whose inferences don’t extend to other cognitive domains, there has been a lot of debate revolving around its format. Results on false belief task indicate an abrupt change during the third year of age. This lead many psychologists and philosophers (see Leslie 1997, Baron-Cohen 1995, Fodor, 1994) to describe the underlying cognitive structure responsible for TOM as an innate module, that is activated around three years of age. As in the case of language, the TOM module is dedicated, specific, fast, automatic, at least partly encapsulated, and its functioning is largely independent of intellectual general capacities of the individual. It can be specifically impaired or function in the presence of other mental impairments. This view fits with the evidence that comes from experimental studies of severe psychiatric impairments as autism, (see Baron-Cohen 1995, Frith, 1994). Autistic children have a significant lower performance on false belief task compared to other cognitive tasks for testing intelligence and language capacities. This lead to the hypothesis that autism could be the consequence of a specific deficit of the Theory of Mind Module (TOMM).

Other scholars (see Carey, 1985; Wellman, 1990) have argued for a "theoretical" model of TOM : instead of seeing it as a mental mechanism, they conceive it as a naive theory, with posits, axioms and rules of inferences. Mental states such as beliefs are theoretical entities, the posits of this theory. In this perspective, often called the Theory Theory it is not possible to pry apart our concepts of mental states from the set of inferences that individuate them within our theory of the mental world, as it wouldn’t be possible to separate the concept of acceleration from those of speed and time in a physical theory. Furthermore, theories change during development : this may lead to genuine conceptual "revolutions", to use the famous Thomas Kuhn’s metaphor for theory change in science (see Kuhn . These radical changes of paradigm make a theory at a certain stage incommensurable with its earlier stages. Some advantages of this position ar e that it better explains the articulation of the development TOM with other children’s abilities as mindreaders, as for example detection of desires (see Gopnik et al. 1994), pretense (see Perner 1991), emotions (see Harris, 1989).

A striking different hypothesis, suggested in the mid-80s by Robert Gordon (see Gordon 1986), is mental simulation, that is, the idea that our capacity of psychological understanding depends on our ability to run cognitive simulations. According to this view, it is possible to infer other people’s intentions and future actions by using our own mind as a model for theirs. All we need is to be able to run a decision process "off-line" : to pretend to be in other people’s shoes and see how our mind would resonate as if we were in the pretended context. Simulation doesn’t involve a complex theory of mind : it involves a capacity of pretense and of putting oneself in the other’s place. Its advantages are (1) that it can easily explain the emergence of pretense at a much earlier stage of development than that of TOM, given that it considers pretense as a completely different cognitive resource, and (2) that it is a much more economical explanation. Crucial ev idence for this model may come from studies on the first-person/third-person ascription of beliefs in children. A series of experiments has investigated self-ascription of beliefs in order to check whether children were better psychologists of their own mental states than of others’. Evidence has been discussed (see Gopnik & Astington 1988, Gopnik 1993) that shows a symmetry between first-person and third-person grasp of intentional states. Children are no more reliable about their own mental states than they are about others’. This seems to suggest that our own mind is not a better model for mental life than others’. However, the discussion still goes on, and other results have been put forward in order to defend the simulation model (see Davies & Stone, 1995).

Evidence from autism

Research in clinical psychology is one of the main areas of application of theory of mind. Autism is one of the most severe psychiatric impairment that can occur during the early stages of development. It is a rare deficit, touching 4/5 children out of 10.000. Its symptoms range from anomalies in social communication, absence of imagination, isolation, lack of capacity to involve in social games, to an almost total impairment of cognitive functions.

In 1985, U. Frith, S. Baron-Cohen and A. Leslie advanced the hypothesis that the central symptoms of autism (anomalies in social interaction, communication and pretense) could be explained by a specific deficit of TOM. They adapted the false belief task to autistic children and ran experiments with a control group of Down children. Although autistic children had better cognitive performance than Down children in many cognitive tasks, they massively failed the false belief task. Furthermore, the amount of successful performance didn’t increase significantly with age. This lead to the conclusion that one central component of autism is a specific deficit in mindreading, and not an impairment of general cognitive abilities.

Still, there is a small percentage of autistic children who actually succeed the false belief task. If autism is defined as a specific deficit of TOM, how is it possible? Experiments have shown that these "talented" autistic fail nonetheless in more sophisticated mindreading tasks, as the second-order false belief task (see Perner & Wimmer, 1985; Happé, 1994) in which subject are asked to attribute embedded mental states as in "Ralph believes that Peter wants that Mary thinks..."). Although they may have some rudimental mindreading ability, they lack the full-fledged metarepresetational capacity that is fundamental for communication (see Sperber 1994b).

Theory of Mind and evolution

Comparative studies with other primates lead psychologists and primatologists to speculate about the phylogenesis of TOM (see Byrne & Whiten 1988; 1997). If TOM is a specific cognitive module, whose function is to detect information within a particular cognitive domain (psychology), it could be the product of a selective pressure that conferred fitness advantages to individuals endowed with mindreading abilities. Furthermore, a complex cognitive module is constituted by sub-modules that may indicate some interesting facts about the phylogenetic history of the module. S. Baron-Cohen has argued (see Baron-Cohen 1995) that TOM recruits other modules for its functioning, as an Eye Direction Detection module (EDD) and a Shared Attention Detection module (SAD). These two modules are clearly present in other species. Comparative studies may lead to a more precise understanding of the evolution of these abilities.

The best known evolutionary hypothesis for theory of mind is the social intelligence or Machiavellian intelligence hypothesis , according to which : "the social environment might have been a significant selective pressure for primate intelligence" (see Byrne & Whiten, 1997, p. 2). Primates show a surplus of intelligence that overcomes the immediate survival needs, as eating, avoiding predators, feeding offspring, etc. According to the Machiavellian intelligence hypothesis this surplus intelligence might have been advantageous for social manipulation, deception and cooperation. This suggests a slightly independent evolutionary history of mindreading abilities from that of language. (see Sperber, forthcoming)