«PhD Thesis Charles Whitehead Department of Anthropology University College London 2003 1 Abstract This thesis attempts to bridge the conceptual gulf ...»
SOCIAL MIRRORS AND THE BRAIN
including a functional imaging study of role-play and verse
Department of Anthropology
University College London
This thesis attempts to bridge the conceptual gulf dividing social from biological anthropology
using three main lines of argument:
1. Enculturated human cooperation originated in expanded systems of kinship and reciprocity which require obfuscation of selfish bodies. Disembodied self perceptions characterize all human belief systems including the behavioural sciences. This prevents our fully appreciating that the most distinctive feature of human behaviour is a formidable armamentarium of social displays. `Social mirrors' underpin human self-awareness, social intelligence, and innate altruism (the ability to identify with others).
2. Social displays engage multiple sensorimotor systems and probably account in part for our large brains. I present a study of role-play and verse, the first in a proposed programme
aiming to map social mirroring functions in the brain. There were three main findings:
1. Cortical areas that are most expanded in humans, and would be expected to show increased activity during role-play, were only apparent when `switching off' role-play
2. The subjectively `easy' control tasks showed greater brain activity than the `difficult' role-play tasks
3. Verse and prose activations were indistinguishable Since role-play activations were not apparent in role-minus-control conditions, role-play may be a continuous mental activity in awake human adults. Cognitive effort may be required to suppress social imagination during non-social tasks. The brief flash of increased activity in presumed role-play areas during the role-to-control switch may implicate dissociation. The findings are at least consistent with a `play and display' hypothesis of hominid brain expansion.
3. A `play and display' hypothesis, compared with cognocentric/logocentric hypotheses, makes better sense of the fossil and archaeological records of human evolution.
2 Contents Page 7 Acknowledgements 8 Introduction
PART 1. SOCIAL MIRRORS AND SOCIAL ORDER12 Chapter 1. The Anthropological `Other' 12 Five features of cultural difference 15 One hundred years of anthropological denials (1) Theories that blame the camera; (2) Theories that invoke real-world experience; (3) Otherworld theories and non-theories 52 Summary and conclusion 57 Chapter 2. Behaviour and Belief 57 Nature versus culture Culture and selfish-genes; Rules, genitals, and bodies; Kinship and reciprocity 60 Five bases of human cooperation (1) Kinship; (2) Exchange; (3) Belief; (4) Self/other-perception; (5) Ritual 93 Summary and conclusion 95 Chapter 3. Social Display 95 Self/other-awareness Theory of mind; Social mirror theory; Theatre of mind; Shared experiential worlds; Language and theatre 107 Social display (1) Three modes of communication; (2) Three modes of play; (3) Three modes of performance; `Symbolism' versus social display 122 Social display and self/other-awareness Social display as a phylogenetic sequence; (1) Social displays in humans and animals; (2) Self/other-awareness in humans and animals; (3) Social displays during childhood development; (4) Self/other-awareness during childhood development 136 Self/other-awareness and society Emergent orders of need; Wholly-believed-in make-believe; Subliminal signals and hypnosis 143 Summary and conclusion
145 Why we have large brains `Intelligence' and language; Play and display 152 Areas of neocortical expansion Primary cortices; Secondary cortices; Major expansions.
155 Current views of the social brain (1) Temporal lobes and amygdalae; (2) Frontal lobes; (3) Parietal lobes 159 Towards a broader concept of the social brain Cognition and behaviour; Motor aspects of cognition; Social and non-social perception; Multimodal integration 171 Mapping social mirroring functions in the brain (1) Implicit performance; (2) Mimetic representation; (3) Conventional communication 189 Summary and conclusion A `play and display' hypothesis of brain expansion 194 Chapter 5. Role-Play and the Brain:
A functional imaging study of role-play and verse 194 Background 198 Method Subjects; Task materials; Task briefing and rehearsal; Study design; Data acquisition; Statistical analysis 206 Results Individual results; Group results 212 Discussion (1) Switching from role to control tasks (RC); (2) Maintaining the non-role state (NC); Interpretation of the `wrong way round' findings; (3) Verse and prose 244 Summary and conclusion
page 246 Chapter 6. Evolution of the Brain 248 The phased pattern of hominid brain expansion Three stages in the evolution of display; Three grade shifts in cranial capacity 294 Summary and conclusion 295 Chapter 7. The Emergence of Modern Culture 295 Was there a `cultural explosion'?
`Symbolic behaviour' and `symbolic culture' 301 The archaeology of social display 304 Evidence from Eurasia and the Middle East Collecting behaviour; Other objects with `added value'; Self adornment;
Use of pigments; Mark-making and geometric designs; Iconic representation;
Intentional burial of the dead 320 Evidence from Africa The first anatomically modern humans; Variability in the MSA; Objects with `added value'; Burials; The difference between Africa and Eurasia; Use of pigments in Africa 340 Summary and conclusion
344 Conclusions 344 The main argument 357 Some final thoughts Play and education; Science and religious experience 365 References 5 Tables page 108 3. 1. Human displays 108 3. 2. Hypothetical evolutionary sequence 125 3. 3. Human and non-human displays 129 3. 4. Ontogenesis of social displays 135 3. 5. Co-development of self-awareness and social mirroring 153 4. 1. Areas of expansion of human relative to chimpanzee neocortex 208 5. 1. Major areas of increased activity during the role-to-control switch 209 5. 2. Major areas of decreased activity during the role-to-control switch 210 5. 3. Major areas of increased activity during control tasks 210 5. 4. Contrasts between switching to a role and role-play 232 5. 5. Activations during `inner speech' and `auditory verbal imagery' compared with deactivations during role-to-control switch 250 6. 1. Geological and archaeological ages 296 7. 1. Earliest appearances of industries/cultures 303 7. 2. Overt evidence of display behaviour in relation to grade shifts and archaeological ages 321 7. 3. Hominids and archaeological ages 339 7. 4. Stone Age/Palaeolithic analogues according to Watts (1999) Figures page 153 4. 1. Areas of differential expansion of human neocortex 174 4. 2. Brodmann's areas activated by musical performance 174 4. 3. `Glass brain' diagrams showing areas significantly more active during ToM tasks than non-ToM tasks 184 4.4a. Brain areas activated when reading written English 185 4.4b. Brain areas activated when reading American Sign Language 203 5. 1. Factorial grid 203 5. 2. Study design showing cycle 1 208 5. 3. `Glass brain' views of activations during the role-to-control switch 209 5. 4. `Glass brain' views of deactivations during the role-to-control switch 210 5. 5. Activations during control tasks contrasted with role-play 211 5. 6. Role-play contrasted with control 211 5. 7. Control minus role-play 214 5. 8. Switching from role-play to control: ventromedial prefrontal cortex 214 5. 9. Switching from role-play to control: inferior parietal cortex 215 5.10. Switching from role-play to control: dorsolateral prefrontal cortex 215 5.11. Inferior parietal lobe in relation to sensorimotor cortices 226 5.12. Right dorsolateral/orbital frontal and prefrontal activations during role-tocontrol switch 235 5.13. Maintaining the non-role state: intraparietal sulci 235 5.14. Surface anatomy of the intraparietal sulcus 251 6. 1. Hominid grade shifts 251 6. 2. Major stone tool industries in relation to grade shifts
The mapping study presented here was conducted at the Wellcome Department of Imaging Neuroscience. I particularly thank Professor R. Turner, Principal of the Functional Imaging Laboratory, for the opportunity to conduct the study, and for his guidance, collaboration, and supervision of the scanning. I also thank Drs. Bal Ashwal and John Ashburner for help with SPM software; Dr. Hugo Critchley for advice on anterior cingulate cortex; Chris Freemantle, Data Manager, for assistance with visuals; and Professor Christopher Frith, Principal Research Fellow, for suggestions on interpretation.
David Craik, Director of Quest Theatre Company and the International School of Screen Acting, and Senior Lecturer in Drama, dedicated many hours to discussing theatrical aspects of my study, recruiting volunteers, and rehearsing their performances for the study. My thanks also go to his present and former students who likewise spent many hours rehearsing the tasks and performing them within the scanner.
In addition I would like to thank my supervisors, Professor Roland Littlewood, Director of the University College Centre for Medical Anthropology and Consultant Psychiatrist at University College Hospital, who has been closely and constantly involved in the preparation of this thesis, and Professor Volker Sommer, of the Department of Anthropology, UCL, for his comments on the evolutionary arguments I present. Professor David Oakley, Director of the Hypnosis Unit, Department of Psychology, UCL, provided guidance and advice on the subject of hypnosis. Thanks also to Helen Gallagher, University of Glasgow, and Helen Neville, University of Oregon, for permission to reproduce Figures 4.3 and 4.4 respectively.
On an average evening, just by watching television, you can see a rich variety of human behaviour, little of which conforms in any obvious way to conventional biological predictions.
Recently I especially noted:
* a cartoon movie in which animals behaved like humans, and much of the humour depended on our intuitive recognition that animals do not behave like
* a news item in which an athlete received a biologically useless gold medal for throwing a javelin and not hitting anything edible such as an antelope;
* a Channel Five `documentary' which showed a half-naked woman copulating with an invisible partner, before an audience of men who made no attempt to compete for the exclusive privilege of inseminating her.
There were also remarkable scenes of cooperation, where rescuers sacrificed their lives to save people unrelated to themselves and from whom they expected nothing in return, or soldiers died in someone else's civil war because they believed Islam was under threat.
Social anthropologists commonly describe apparently unbiological human behaviour as `symbolic'. Biological anthropologists tell us that genes do not necessarily operate in the environment to which they are best adapted, or that `mental modules' may be `closed' or `open'. I am not sure that either is giving us anything very helpful if we want to understand what human culture is or how it works.
of human culture. I will argue that much of what we call `culture' is wholly-believed-in makebelieve, and that human self/other-awareness depends on social play and display, including song, dance, art, and role-play.
My PhD research, a functional brain imaging study of role-play and verse, is presented in Chapter 5. The other six chapters contextualize and explore the implications of my research. My aim is to bridge the conceptual gulf currently dividing social from biological anthropology, using cognitive science, and to show what all three disciplines can gain from a better understanding of each other. I will also show that all three disciplines are hampered by disembodied perceptions of the self, and that these have curious parallels in animistic belief systems. Obfuscation of the body would seem to be a major mechanism of enculturation. Why else, for example, should we always wear clothes in public, even in the swimming pool?
1. Social mirrors and social order The first part explores the nature of human culture and emergent order, the peculiar problems faced by enculturated scientists attempting to understand culture, the reasons why social anthropologists do not agree with biological anthropologists, and why we need a more anthropologically informed cognitive science (Chapters 1 and 2). Chapter 3 introduces social mirror theory as the potential bridge between social anthropology, biology, and cognitive science, and the basis of a more embodied understanding in the behavioural sciences.
The second part examines some current blind spots in cognitive neuroscience, attempts a broader understanding of the social brain, and proposes a `play and display' hypothesis of human brain expansion (Chapter 4). I then present my own research on role-play and verse, which appears to be at least consistent with the hypothesis (Chapter 5).
3. Evolution of social mirrors and the brain The final part (Chapters 6 and 7) looks at human evolution and the emergence of modern culture in the context of a `play and display' hypothesis.