Robin Dunbar
The Human Story
A new history of mankind's Evolution
faber and faber 2004

...the essence of what made us who we are, what finally produced humans as we know them, with all that inflorescence of culture that makes us in some intangible but very certain way utterly different from every other species alive today - and, indeed, every other species that preceded us in the long history of life on earth.

This is a journey within ourselves. To understand what it is to be human, we have to understand our own minds. It is here, in our ability to reflect upon ourselves and our relationship with the world 'out there', that the real differences between us and the rest of creation seem to lie. Our physical attributes and a great deal of our behaviour are unexceptional, even by the standards of an unexceptional group like the primates. Rather, what sets us apart is, above all, a life in the mind, the ability to imagine.

pg 43
...children's developing abilities for inferring the mental states of others. They represent a critical Rubicon in the process of child development because they demarcate the moment at which children can begin to engage with an imaginary world that is not physically present. They can now begin to engage in those forms of pretend play...

...philosophers interested in the nature of minds coined the term 'intentionality' to refer to the kinds of mental states that we have when we are conscious of holding some kind of belief, desire or intention. The term refers collectively to mind-states like knowing, believing, thinking, wanting, desiring, hoping, intending, etc. It refers to the state of being aware of the contents of your own mind. Intentionality can be conceived of as a hierarchically organised series of belief-states. In this scheme of things, computers are zero-order intentional entities: they are not aware of the contents of their 'minds' Some living organisms such as bacteria (and perhaps some insects) may also be zero-order intentional beings. Most organisms that have brains of some kind are probably aware of the contents of their minds: they'know' that they are hungry or 'believe' that there is a predator under that bush over there. Such organisms are said to possess first-order intentionality. Having a belief about someone else's beliefs (or intentions) constitutes second order intentionality, the criterion for theory of mind (or, as it is more often known in the technical literature, ToM). Jane believes that Sally thinks her ball is under the cushion. Jane has two belief states in mind (her own and Sally's), so theory of mind is equivalent to second-order intentionality. intentionality to fifth-order intentionality

pg 65

One of the very conspicuous features of our mental world is the way we rehearse what we are going to do. This often entails explicitly considering alternative options, evaluating their likely outcomes and, having chosen one, rehearsing how we can best approach its execution. This process is so much a part of our mental life that we barely give it a moment's thought. But perhaps it provides us with the clue we have been looking for.

This kind of mental rehearsal is actually quite a complex task and involves bringing into play a number of quite different cognitive abilities. At the very least, these include the ability to reason causally (to follow the sequence through from cause to likely effect), to reason analogically (to recognise that A is to B as X is to Y), to run several alternative scenarios in parallel and, finally, to do so on an extended time frame into the future.

Analogical reasoning may play an unexpectedly crucial role in the story of the human mind because it provides us with a platform for understanding other minds.

...when it comes to understanding the nature of the relationship between two individuals, we have to deal with something that we cannot experience directly. As the ethologist Robert Hinde pointed out more than three decades ago, we abstract relationships out of the observations we make of individuals interacting. Relationships are things that happen only in a virtual world, and we have to be able to move backwards and forwards between the physical world of interactions (real events) and the virtual world in which these events are constituted into relationships in order to be able to understand what the significance of specific actions is or might be, or how two relationships impinge on each other.

for full-blown human-style social cognition, all four abilities have to be brought into play together: having only some of them is useful, but it does not allow you to engage in the kinds of complex thinking that goes into fourth- and fifth-order intentionality.

functions of the frontal cortex

...during the course of primate evolution, the brain has expanded forwards from back to front, so that the bit that has increased out of all proportion in modern humans is the frontal lobe. The bits at the back and sides of the brain are mainly devoted to vision and other aspects of sensory perception, sensory integration and memory. It is the increased size of the frontal lobes that is largely responsible for the much greater intelligence of species like apes and humans.

When did our ancestors pass through the critical Rubicon at which theory of mind and higher orders of intentionality became possible?

...although apes and humans share a number of important advanced cognitive abilities, they differ in one key respect: the extent to which humans can detach themselves from the world as they experience it. This allows humans to reflect on the world as they find it, to wonder whether it could have been otherwise. In contrast, apes (and certainly all other animals) have a much more direct, straightforward experience of the world. Their noses are thrust firmly up against reality. In the following chap­ters, we shall see that this has very important implications for some of the more explicitly human aspects of our behaviour.

pg 109

...humans differ from all other species of animals - including our ape cousins - in one obvious respect: language.

social brain hypothesis - Language allows us to keep track of what is going on in the constantly changing world of our social relationships. Who's in and who's out, who isn't behaving as they should, who's showing signs of becoming a promising candidate to be our friend...

pg 121

When did Speech Evolve?
...these analyses bracket the date at which speech evolved. The size of the thoracic nerve canal places the earliest possible date as some time after 1.6 million years ago (the last fossil in the sequence with an ape-like thoracic canal). Given that both Neanderthals and Cro-Magnons have modern­sized hypoglossal and thoracic nerve canals, the simplest expla­nation is that they inherited these traits from their common ancestor, archaic Homo supiens. Hence, the latest possible date must be the appearance of that common ancestor, around half a million years ago.

...In sum, then, it seems that speech (and hence language) must have been in place by the appearance of Homo sapiens half a million years ago, at least in some form. Whether this would have been language as we know it today is a moot point. A plausible interpretation of the evidence suggests that speech/language did not evolve suddenly out of nowhere (as many linguists have assumed) but rather developed piecemeal to fill the bonding gap left by grooming once group size exceeded the size that could be bonded in the conventional primate manner. This raises the possibility that language actually went through a vocal phase that was not linguistic - in short, one that was musical rather than verbal. some point during the course of human evolution, we borrowed the chimpanzee playface and its associated vocalisations and exaggerated them to provide the reinforcer for grooming at a distance. Since the brain areas involved in laughter and language seem to be very different - indeed, they are not even in the same hemisphere of the brain - laughter may well have evolved long before language. The fact that laughter is so contagious perhaps suggests that it was used in a kind of communal ritual alongside non-verbal vocalisations like conventional primate contact calls. Later, of course, the acquisition of language allowed us to use verbal constructions to stimulate laughter in others more effectively. Jokes, it seems, have a very ancient heritage, much older in all likelihood than anything else we do with language

Laughter seems to be a good releaser of endorphins

Like grooming, it seems that laughter encourages you to stay put and continue the interaction with a particular partner. It floods the brain with endorphins and just makes you feel positively disposed towards the other person.

pg 131
Why should music do this to us and what role has it played in the story of human evolution?

The answer to the first question is still shrouded in mystery. But it seems that some musical tones do trigger off deep responses somewhere in the brain. Aside from the more obvious activity to be expected in the auditory cortex where all sounds are processed, the main responses are in the right hemisphere and in regions in the evolutionarily more ancient limbic system. Since that is the opposite side of the brain to where language has its main centres (the leit hemisphere), it seems plausible to infer that music and language have had separate evolutionary histories. Indeed, the deeply emotional stirrings generated by music suggest to me that music has very ancient origins, long predating the evolution of language, and this per­haps gives us a clue as to how we might answer the second question on music's role in our evolutionary history.

Are these trance states some kind of self-induced opioid high? Is this why we so enjoy dancing, a phenomenon that probably ranks, along with smiling and laughter, as one of the most futile of all human universals? Were dance and singing, and perhaps the rhythmic clapping of hands that so often accompanies both of these, an early supplement to physical grooming that allowed Homo erectus to enlarge its groups beyond the limit imposed by the immediate time constraints on grooming?

We clearly differ from our ape and monkey cousins in our use of language. However, many of the core features of language, and the associated non-verbal components that make conver­sation possible, bear important similarities to the kinds of social communication we find in other primates. That we use language to exchange complex technical information is undoubtedly important, but it seems likely that this was a relatively recent development. Speech and language evolved to enable us to bond social groups that were getting too large to bond by conventional primate social grooming. We seem still to use it mainly for these purposes. Moreover, in order to enable language to do this job effectively, we have to draw heavily on some non-verbal features (laughter and music) that take us straight back into the chemical processes that underpin grooming. However, with laughter and music, we are at last beginning to find elements which, if not uniquely human, do at least find expression among hurnans with a frequency and intensity that are perhaps unique

pg 159

A Very Cultured Ape

Impressive as these examples of chimpanzee culture are - and I really have no problem about using the term 'culture' when talking about them - they remain, in the final analysis, unsatisfying. For one thing, it is the relative scarcity of genninely cul­tural behaviour that is troubling. A grand total of 39 elements of cultural behaviour from the hundreds of thousands of hours of chimpanzee-observation in the wild and in captivity is not an impressive tally. Were we to conduct the same experiment on humans, we would surely find so many examples of differences that the chimpanzee catalogue would fade into insignificance, even if it was ten times as large as it currently is. But, there is another and more troubling absence in the great ape story: we still see nothing that smacks of those activities that form so fundamental a part of human culture - story-telling and music, and beyond them that whole panoply of religion and ritual, and the significance of a spirit world that sits apart from the real world in which we all live.

Dunbar 167

Religion would seem to be a truly universal trait among humans. Every human tribe that has ever been encountered has some form of belief in a spirit world and most (but maybe not all) have some sense of an afterlife. All engage in rituals and prayers intended to placate, cajole or entice the denizens of that unseen world to look favourably on the poor long-suffering members of the human race. At the same time, we have no evidence of any kind that would seriously suggest that any other species aside from ourselves has anything remotely resembling religion. This is not simply because other species lack language. Language is important in formalising religion within a community, in allowing us to agree on the nature of the gods in whom we believe and the afterlife that we hanker for. But this is not what makes religion or religious belief in the individual possible.

There are three quite distinct questions we can ask about human religious experience:
(1) Why are we the only species to have religion and believe in a parallel world? (2) What function did religion serve for our ancestors, and to what extent does it still serve that function for us today?
(3) When did religion first appear in human history?

Even a cursory glance around the world's myriad religions should convince us of one thing, and this is that religion serves several different, bot often equally important, purposes in the lives of recent and modern humans. These functions would seem to be:
(1) providing coherence for the world in which we live (a metaphysical scheme that explains why the world is as it is, and thus makes sense of it for us);
(2) allowing us to feel we have greater control (throngh prayer and other rituals) over the vagaries of life than we would otherwise do;
(3) enforcing rules about how we should behave in society (ethics and moral systems); and
(4) allowing a minority to exert political control over the community.

I detect in these two quite separate agendas. One seems to be associated with trying to allow us to cope with a world that is not always as benevolent towards us as we might wish. The other seems to have much more to do with social control in a very broad sense.

Cognition - Kognition - Sprachgeschichte