Evolutionary Psychology Lecture 12: Theory of Mind (ToM).

1. Evolutionary Psychology Lecture 12: Theory of Mind (ToM).

2. Learning Outcomes. • At the end of this session you should be able to: • 1. Evaluate the evidence concerning the existence of self-awareness and ‘theory of mind’ in animals. • 2. Discuss evolutionary explanations for the development of ‘theory of mind’ in humans.

3. Intentional Understanding • Humans display an automatic and pervasive set of behaviours that revolve around the interpretation of the behaviour of the self and others in terms of inferences about unobservable mental states. • Humans assume that other people are intentional agents who possess a mind very similar to our own, we treat them as having mental states – opinions, thoughts, fears, emotions, beliefs, intentions (Povinelli & Preuss, 1995). • We are skilled at predicting other people’s intentions, spotting a liar or cheater, realising that someone is unhappy or afraid etc.

4. Theory of Mind (ToM). • We therefore possess the ability to understand and act upon the fact that other individuals possess a mental state which may differ to that of ourselves. • These mental states are: • 1. Independent of the real world (we can all believe things that are not true). • 2. Independent of the mental states other people may have (we all believe, desire and pretend different things from one another). • This ‘mind reading’ ability is referred to as ‘Theory of Mind’ (ToM) and was originally proposed by Premack & Woodruff (1978).

5. How Important is a ToM? • Baron-Cohen (1999) pointed out the importance of a ToM and lists a series of behaviours that depend upon it: • Intentional communication with others. • Repairing failed communication with others. • Teaching others. • Intentionally persuading others. • Intentionally deceiving others. • Building shared plans and goals. • Intentionally sharing a focus or topic of attention. • Pretending. • Such behaviours are consistently impaired in autism and as yet, there is no clear evidence that they are consistently seen in our close relatives (monkeys and apes).

6. The Development of ToM. • Barresi & Moore (1996) summarised the development of the understanding of intentional relations in humans: • 2 months: Infants become interested in social stimulation and can engage in social interactions (e.g smiling). • 4-5 months: they pay attention to non-social objects but do not coordinate person-directed behaviour and object-directed behaviour. • 12-18 months: Engage in proto-declarative pointing (drawing the attention of someone else to an object by pointing at it) and can track another persons line of gaze. • These behaviours indicates that the infant is developing a concept of another person as an 'intentional agent'.

7. The Development of ToM (continued). • 18-24 months: The emergence of conceptual knowledge of the self emerges and we see the following: • Recognition of self in mirrors. • Symbolic play. • Simple acts of altruism (giving a toy to another child). • Reciprocal co-operation with others (sharing, simple co-operative play). • Linguistic comments about the failure or success of self-generated plans. • Mastery smiles upon the completion of a task. • Use of mental state terminology to refer to desires.

8. Understanding of False-Belief • Between the ages of 3-5 children understand that beliefs are individual mental representations. • They also understand that someone else may hold a belief that differs to their own. • This ability can be demonstrated using false-belief tests such as the 'Sally-Anne test' (Wimmer & Perner, 1983). • Baron-Cohen et al., (1985) tested 20 autistic children on this task and found that 80% failed to appreciate Sally’s false belief and said she would look in the box. • In contrast, normal children, children with language impairments, and children with Down’s syndrome succeed on this task.

9. The ‘Sally-Ann Test’. From Happé, 1994, p41

10. The Evolution of ToM. • A key question concerns whether ToM has only evolved in humans, or whether ToM evolved before the divergence of humans. • If the latter is the case then we would also expect to see ToM capabilities in our near relatives. • According to Humphrey (1978), self-knowledge, and through it the intuitive knowledge of others, have made an essential contribution to the reproductive fitness of social animals. • In complex social groups the ability to understand and predict another individual’s behaviour would be an enormous advantage. • This complicated skill would require superior intelligence (as seen in social animals) and both would evolve through natural selection.

11. Self-Consciousness. • Dennett (1996) argued that self consciousness can be seen as a hierarchy of intentional systems: • First order: having beliefs and desires about many things, but not about beliefs and desires (most animals, human infants, autistic individuals?). • Second-order: having beliefs and desires about beliefs and desires, of self and others (humans, other primates?). • Third-order: having the capability of such feats as wanting another individual to believe that you want something (humans, other primates?). • Fourth-order: having the capability to make another individual believe you want it to believe that you believe something (humans only?).

12. 2nd Order Understanding. • The giant leap of being able to generalise about other individuals comes between stages 1 and 2. • An interesting question is “How did some social animals make this leap?”. • Dennett (1996) points out that a likely candidate is communication, and especially in humans the emergence of language. • Communication enables social competition, exchange, alliance building, transmission of important information, culture, and deception. • “Language was invented so that people could conceal their thoughts from one another” • (Charles-Maurice de Talleyrand).

13. Baron-Cohen, (1999). • Unlike Dennett, he believes that a ToM must have preceded language, as without ToM being able to speak or perceive speech would have been of little value. • For example, autistic children possess language, it consists of syntax, vocabulary and semantics, but lacks pragmatics - the ability to decipher someone's intentions from their speech. • He further argues that ToM certainly existed around 40,000 years ago and it must have been present around 100-150,000 years ago during the dispersal from Africa, but before then there is little firm evidence of its existence. • He argues that apes clearly show social intelligence but this does not necessarily mean that they possess a ToM.

14. Deception. • Much of social life is concerned with hiding our true intentions. • A complex social environment led to the need for deception, which led to increased social intelligence, which led to language and symbols, which led to higher-order self-awareness and an advanced theory of mind. • Machiavelli was a Florentine diplomat whose name has become synonymous with a strategy of social conduct in which others are regarded entirely as a means towards a personal end. • Human social intelligence may have evolved in order to understand, predict and manipulate the behaviour of other people.

15. Psychological Qualities of Machiavellianism. • Individuals scoring highly on Machiavellian traits are called ‘High-Machs’ and according to Wilson et al., (1996) display the following: • Are perceived as being more intelligent, socially attractive, and charming. • Take centre-stage and adopt leadership roles. • Easily beat 'low-Machs' in bargaining and alliance-forming situations. • Are more likely to use exploitative and manipulative tactics in group situations, and are more successful in short-term, face-to-face interactions. • Are less likely to empathise with others, or help others in an emergency. • Are more believable liars, maintain greater eye contact and confess less often.

16. Somatic Marker Mechanism. • Damasio (1995) referred to the neural mechanism for TOM as the ‘somatic marker mechanism’ (SMM). • This involves the use of one’s emotional reactions as indicators of another person’s mental state. • E.g if the approach of a stranger induces an emotional response of fear, a combined emotional-perceptual representation of ‘hostile stranger’ is created in working memory. • If at a later date these perceptual representations are reactivated from memory, the linked emotion of fear will also be deployed.

17. Do all Humans Possess a ToM? • Individuals who lack a ToM will be fundamentally disadvantaged in social situations as they will be unable to predict the intentions of others. • In some people the ToM mechanism is either absent or dysfunctional (autistics) and they show: • Lack of awareness of the existence or feelings of others. • Lack of social, imaginative play, they mainly play alone. • Gross impairment in the ability to make friends. • They do not understand jokes. • Abnormal non-verbal and verbal communication. • Impairment in initiating and sustaining conversation. • They follow routines rigidly and hate change. • Restricted and obsessive range of interests – usually object based.

18. Evidence for ToM in Primates. • 1. Self-Awareness. • If presented with a mirror, most animals (and human children below 2) react as if confronted by another animal. • Even if exposed to the experience of seeing a mirror on a regular basis, most animals never show evidence of self recognition. • Chimpanzees and orang-utans can learn that the reflections are representations of themselves, as they use the mirror to inspect parts of their bodies that they cannot see. • Gallup (1998) argued that animals who possess self-awareness can use such experiences to model the experience of others (empathy).

19. Self-Awareness? From Gallup, 1998, p 70

20. 2. Empathy. • Povinelli (1992) devised a task in which one human could see which of two handles would give food rewards when pulled, but could not reach the handles. • To succeed, the individual has to indicate the correct choice to a second individual, who can reach the handles but who cannot see which one is correct. • Chimpanzees but not rhesus monkeys could learn either role, and switched roles as necessary. • Povinelli et al., (1994) allowed a chimpanzee to choose the advice of one of two human helpers in deciding which container is baited with food. • Only one human saw the baiting, and chimpanzees accurately selected the human who had seen the baiting as their helper.

21. Povinelli et al., (1994) Study. From Byrne, 1995, p108

22. Alternative Explanations. • Povinelli et al., (1998) provided chimpanzees with a choice of someone who could see them and someone who could not. • The animals behaved in a random manner, sometimes selecting the ‘sighted’ helper, but other times selecting the ‘unsighted’ helper. • In another experiment the experimenters sat with their backs to the chimpanzee, but one looked over her shoulder at them. • Again performance was random. • They also found that chimpanzees may not comprehend pointing gestures as referential actions.

23. Alternative Explanations (continued). • Povinelli (1998) also provided an explanation for chimpanzee success in mirror tasks. • He argued that success is based on recognition of self-behaviour, ie when chimp’s see themselves in the mirror they form an equivalence relation between the actions they see and their own behaviour. • They conclude that everything that is true for the mirror is also true for their own bodies and vice versa; thus they can correlate coloured marks on the mirror image with marks on their own bodies. • They don’t conclude ‘that’s me!’, rather they conclude ‘that’s the same as me’.