Theory of mind
The phrase "theory of mind" can be used in several ways.
- There are general categories of theories of mind.
- There are the specific theories of mind attributable to individuals.
- "Theory of mind" has also been used (following David Premack and G. Woodruff, 1978) to refer to a specific cognitive capacity; the ability to understand that others have beliefs, desires and intentions that are different from one's own.
General categories of theories of mind
In Functionalist theories, functionalists like Georges Rey explore Computational Theories of Mind (see external links, below) that are independent of the physical instantiation of any particular mind.
In Brain-mind Identity theories, Biologists like Gerald Edelman are concerned with the details of how brain activity produces mind and work within the confines of the Identity Theory of Mind (see external links, below).
Theories of mind attributable to individuals
We can also talk about theories of mind produced by individuals, such as Brentano's Theory of Mind. Goerges Rey and Gerald Edelman were mentioned above as examples of people who deal with different broad categories of theories of mind within which they have each produced their own personal theories of mind.
"Theory of mind" as a specific cognitive capacity
In 1978 D. Premack and G. Woodruff published an article called Does the chimpanzee have a theory of mind? (Behavioral and Brain Sciences 4:515-526) which introduced the use of the phrase "theory of mind" to refer to the cognitive capacity that allows each of us to know that other people have their own unique thoughts that differ from our own. This cognitive capacity normally develops in young children as their brains mature and they acquire an increasingly sophisticated understanding of complex human social behaviors. Evidence from behavioral studies indicate that very young children usually assume that other people know what they know. Acquiring the understanding that each person has their own thoughts is an important developmental step for children.
As the title of Premack and Woodruff's 1978 article indicates (see above), it is also important to ask if other animals besides humans have a genetic endowment and social environment that allows them to acquire a theory of mind in the same way that human children do. This is a contentious issue because of the problem of inferring from animal behavior the existence of particular thoughts. Each of us knows by introspection that we understand that others have beliefs, desires and intentions that are different from our own and we infer that all humans with normal minds share this cognitive ability. Researchers who have spent a great deal of time with non-human apes tend to accept the likelihood that other apes like chimps also have a theory of mind. For example, Sue Savage-Rumbaugh takes this position in her book "Kanzi". Others such as C. M. Heyes (see [http://www.bbsonline.org/documents/a/00/00/05/46/index.html Theory of Mind in Nonhuman Primates]) take the position that we need not infer that chimps in the wild have any understanding of the mental states of other chimps.
There is interest in the idea that certain learned behaviors such as human language behavior, facilitate the development of a theory of mind in both humans and chimps. In the context of language users, Sue Savage-Rumbaugh (Kanzi, page 272) has described "theory of mind" as the idea that "knowledge states of the speaker and the listener can in fact be different."
There has also been speculation that certain humans fail to progress through the normal cognitive developmental stages that lead to acquisition of a theory of mind. In 1985 Baron-Cohen, Leslie and Frith published an article called Does the autistic child have a "theory of mind"? in which it was suggested that the human brain normally has a "theory of mind module" and that this particular component of the brain may not develop normally in some people. With the advent of brain imaging techniques, particular brain regions that seem to be important for theory of mind have been identified.
Autistic people often develop the theory of mind late, or not at all. However, some autistic people claim that the theory of mind that they have developed is superior to that of a normal person. The theory of mind that normal children develop appears to be that other people have different knowledge from oneself but process their knowledge in the same way that one would. The usual test for theory of mind, the "Sally-Anne test", is biased towards that type of theory of mind. Autistic people who develop a workable theory of mind tend to be aware not only that other people have different knowledge from themselves but also that other people have a different way of thinking. This second aspect of theory of mind is not commonly tested for. It is not yet established whether this different theory of mind is inherent in the autistic way of thinking or a result of the usual autistic experience of growing up among people with a very radically and obviously different way of thinking. It has also been suggested that the autistic delay in development of theory of mind is to some degree attributable to the difficulty of having to develop this more complex theory.