On a Theory of Mind in relation to our hominin ancestors
The concept of Theory of Mind (ToM) has significant implications not only for the understanding of fossil hominins development, but for studies into modern populations of both humans and non-humans. The idea behind the theory, which is a phrase coined by Premack and Woodruff (1978) is the ability to be aware of another being’s mental state. This involves understanding what another individual is thinking at a certain time, to ascribe feelings, beliefs, fears, desires and hopes to someone else, and to know that they really do experience these feelings as mental states. Wertz and German highlight that it means not just recognising beliefs and desires in others, but our ability to explain their actions (Wertz and German 2006: 184).The reason this concept is so interesting and debatable from an evolutionary point of view is that it requires a degree of introspectiveness: the ability to look within oneself and observe mental and emotional states.
A key word in all studies of the presence of ToM is empathy. This ability to feel anguish, distress or pain in response to a scenario occurring exteriorly to the viewer, with someone else, indicates an innate ability to view occurrences from differing perspectives. The idea of empathy being present in species possessing a ToM lead to studies looking into the science behind the idea of empathy. Originally identified in the premotor cortex of macaques, the term ‘mirror neuron system’ (MNS) was coined, which referred to the neurons of the brain that “fire both when an agent executes a particular action and when that agent observes another agent executing the same action” (Grove & Coward 2008: 389). The phrase ‘mirror’ refers to the fact that the response felt by the viewer reflects that of the viewed. For example, a study looking at observation of pictures of a hand reaching to grasp an object (Urgesi et al: 2006) found that this activated the motor representation of grasping in the observer’s brain.
The MNS has had important implications for research into the development of ToM in Homo Sapiens’ ancestry, and the development of communication and language. MNS in humans has been found to be directly involved in the perception of communicative facial actions, where studies observe the reactions of the MNS of participants watching a picture of a human face displaying different emotions (Freedberg & Gallese 2007: 200). This study’s verdict is supported by others, who claim that “without a theory of mind, having the ability to speak or perceive speech would have been of little value” (Baron-Cohen 1999: 261).
The concept of Theory of Mind is divided into a hierarchical system, composed of different orders of ‘intentionality’. Things that have no recognition of even their own mental state are referred to as having ‘zero-order’ intentionality (Dunbar 1996: 84). It is supposed that this unawareness of one’s own mental state is present in insects and invertebrates, although it would seem that studies into this hypothesis would be challenging or impossible to carry out. Therefore, first order intentionality must be present in species that have an awareness of themselves. Writings on this first order often reference the statement by René Descartes (Figure 2) ‘Cogito ergo sum’ (I think, therefore I am). Gordon Gallup acknowledged that a key factor that characterises us is that “we can recognise ourselves as a separate entity from the other individuals with whom we live” (Dunbar 1996: 91).
This awareness of one’s own self is present in almost all species, which is why many primate studies looking into intelligence and social interaction have focused on second (and third order) intentionality. The existence of at least second order intentionality in primates (as well as elephants and dolphins) has been proven by multiple studies (Savage-Rumbaugh & McDonald 1988, Goodall 1971), and is indicative of the ability to hold a belief about someone else, and even believe that they might believe something about you. The third and fourth orders of intentionality, although apparently present in some primate studies, appears to be the origin of the concept of imagination and fiction, of myths and imagined geographies, allowing us to visualise how someone who does not exist might behave (Dunbar 1996: 102).
In relation to the development of Homo Sapiens, Dunbar states that without a fully developed ToM we would not have evolved and advanced in the way we have. The concept involves detaching oneself from the immediacy of one’s experiences. Therefore by definition, phenomena of religion and science would be impossible without the abilities which ToM grants. Both are means of questioning our own existence and seeking to explain “why the world is as we find it- their functions remain the same as each other” (Dunbar 1996:104). To pose the question of how you, or your species, came into existence requires this concept of imagination within the mind. The idea that the world could be other than as it seems from a first person perspective, comes from our ability to understand how individuals’ minds can influence one another, requiring third order intentionality at the very least. If science and religion require fourth order intentionality then it is clear why only humans have produced them. By referring back to the idea of MNS and the development of language we can gain some insight into when fossil hominins may have established a ToM. Without sophisticated language, we cannot convey ideas of religion or science (Figure 3). Dunbar sums it up well by saying “If chimpanzees have religion, they must have as many religions as there are individual chimpanzees” (Dunbar 1996: 105).
In modern humans, ToM offers important insights for child psychology, particularly in analysing autism in children, and their inability to recognise the thoughts and emotions of others. Extensive studies into the age in which ToM develops have shown that between the ages of 3 and 4 the child changes from being able to recognise and recall information only from their own perspective, to the ability to visualise scenarios from the viewpoint of others: in other words they develop a sense of empathy. Studies into this have involved using ‘false belief’ tests, whereby the child is observed in whether or not they are aware someone can hold an incorrect or fictional belief about a certain scenario (Dunbar 1996: 86).
The ability to recognise someone’s desire (desire reasoning) precedes belief reasoning by one and a half years. This has been supported by a study which found that 18 month old infants had a limited ability (but an ability nonetheless) to reason non-egocentrically about people’s desires. However, when it came to belief reasoning and further orders of intentionality, it was found that 3 year olds failed to understand that a person’s mental representation of reality can differ from actual reality (Sodian & Kristen 2010: 190). It was apparent that ToM was not present at this age, as the 3 year olds “assume that you see everything they see, and interpret it in much the same way” ; they are not aware that your state of mind, your beliefs, can be manipulated (Dunbar 1996: 85). The idea of fiction and myth being indicators of a ToM is supported by Scott and Baron-Cohen (1996), who found that children with autism struggled to draw a fictional entity of ‘a man that could never exist’ but were able to sketch scenes observed through first order intentionality.
If, as mentioned earlier, the concept of empathy reflects a presence of ToM, through the ability to be aware of the emotions of other, then studies could potentially analysis its occurrence in fossil hominins. Such a study has been carried out on a Neanderthal male (Shanidar 1), intentionally buried in Shanidar Cave in Iraq (Pettitt 2009: 151). Osteological examination of the skeleton revealed the man was blind in one eye due to serious injury, had no right hand and paralysis down the right side of his body. The injuries were all found to have occurred years before his death, indicating empathy from the social group as they provided and cared for this man (Smithsonian Institute 2012).
As previously mentioned, the idea of introspectiveness must have been crucial to the beginning of a ToM in our fossil ancestors. “The starting point of ToM was probably our ability to reflect back on the contents of our own minds. Understanding our own feelings is crucial to understanding those of other people” (Dunbar 1996: 101). A theme to highlight at this point is that it is generally agreed early human ancestors such as Australopithecus, Homo Habilis and Homo Erectus possessed some primary form of ToM through empathy, communication and recognition of others. However, the origins of ‘Kinshipping’ that is: “the ability to move through time and space by means of relationships and exchange” (Shryock, Trautmann and Gamble 2011) came after the extinction or evolution of these earlier species (1.5–0.4ma). This could have coincided with cognitive development leading to the introduction of a more advanced ToM, and the creation of ideas of religion and ‘imagined geographies’ associated more with Homo Sapiens and Homo Neanderthalensis.
A number of studies have been carried out by Plotnik et al that looked into the possibility of a ToM in Asian elephants. Using study scenario techniques originally developed for chimpanzee intentionality experiments, they were able to show that the elephants would co-operate and use teamwork by pulling ropes simultaneously in order to access a food source (Plotnik 2011). This shows the ability in these animals to carry out a social level 2 task: the ability to recognise and collaborate with another mind. Another study by Plotnik looked into the presence of first order intentionality in Asian elephants; whether they were able to recognise their own existence via Mirror Self-Recognition (MSR) tests (Figure 5). A large mirror inside the enclosure and a marker placed onto the elephants head allowed the study group to establish whether the animals possessed an awareness of itself as a living being (Plotnik 2006). MSR tests have also retrieved successful results from apes and dolphins. Plotnik points to these inter-species parallels as indicating convergent cognitive evolution as evidenced by the cooperation and social complexity of these species. However, MSR tests have been criticised for their lack of ecological validity; mirrors do not exist in the natural world of animals so should not be used as a measure for self-awareness (Dunbar 1996: 92).
The idea of a form of ToM being present in non-human primates is one which has been much debated. Mithen claimed that the concept must have originated no less than 6 million years ago. His ideas were based on the fact that our last common ancestor with modern apes lived around this time and, he argued, must have possessed a ToM in order to pass the trait on to all subsequent branches of the evolutionary tree (Mithen 1996). However, others have disputed this claim, questioning whether modern apes do actually exhibit a fully developed ToM. If this is in fact the case, psychologist Simon Baron-Cohen argues that “theory of mind proper was certainly evident 40 000 years ago, but before then there is no substantive evidence for its existence” (Baron-Cohen 1999: 262). Although 40 000 years is a conservative estimate, if a developed ToM was the precursor to the beginnings of language, as several authors have suggested, it seems likely that that it developed after our 6ma divergence from our closest living ancestors. Accepting the fact that a type of ToM must have heralded he arrival of language, and therefore religion, the comparatively recent evidence for some kind of religious or ritual belief in the archaeological record may support Baron Cohen’s theory of a later origin of a fully developed ToM such as we see in modern humans.
Noam Chomsky claimed that language acquisition in human children was an innate evolutionary neural capability, called a Language Acquisition Device. He even went on to question the role of behaviouralist learning in a child’s language acquisition, asserting that it was purely biological (Chomsky 1962). Evidence for some kind of neural facilitation of language learning seems convincing, since “no other species, including apes, has been able to master the process of language production” (Quiatt & Reynolds 1995: 14).
However, characteristic criteria of a species with a developed ToM, such as the ability to persuade, intentionally communicate and deceive, and the ability to pretend (Baron-Cohen 1999: 262–265), appear to have been observed during some primate studies (Figure 6). In a study by the psychologist and primatologist Savage-Rumbaugh, Austin the chimpanzee was able to deceive his companion, Sherman, by pretending to be afraid of fictional hazards in the night, in order to gain hugs and comfort from him (Savage-Rumbaugh & McDonald 1988: 28). This would appear to be a clear indicator a complex ToM, with at least a third level of intentionality. However, as with many primate and non-human studies, questions are asked over the issue of anthropomorphism, whereby human motives are used to explain animal behaviour (King, Rumbaugh & Savage-Rumbaugh 2009: 99). Did Austin know that he was creating a fictional hazard in order to scare Sherman, or had he merely learnt through trial and error that by rattling the metal bars he could gain favour and attention from his companion? This critique of primate studies is supported by the statement that close relationships between the teacher and subjects are unavoidably central to the communications under study (Quiatt 1990). That is to say, can we assume general conclusions for the whole of the chimpanzee species cognitive abilities and possible presence of ToM, based on captivity — bred subjects used to close human interaction?
The concept of TOM seems to vary between sources, some stating that it merely reflects the ability to recognise the actions of others, while others deciding that ToM is only present in species which can explain these observed actions. These divergences in definition may be the reason for the continued differences of opinion between various studies. My understanding of the concept of Theory of Mind is that it is not a physical object which you have or have not, but a spectrum of conceptual understandings (hence its apparent presence in small-brained macaques). Therefore, only a fully developed ToM triggers the arrival of language and with it the third and fourth order ideas of imagination.
The concept of Theory of Mind has a wide and diverse range of implications, crossing boundaries from archaeological studies into biology and psychology. Studies looking into the creation of mind in modern humans, and the effects of neural development disorders like autism on this process have, in general, been successful in establishing positive results. More difficulty arises in studies of the occurrence of ToM in fossil hominins and primates, as critics have disputed the validity and therefore their conclusions. It seems unlikely that a definite agreement will be reached on the age at which this concept developed, although further research will no doubt continue to make grounds.
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