Category Archives: Evolution

Cognition and Consciousness in Peter Pan

A Conversation with Rosalind Ridley

My friend and colleague, Rosalind Ridley, who has had a distinguished career with the MRC studying brain and behaviour, has just published an intriguing book about J M Barrie and Peter Pan. It turns out that Peter Pan is not just a childish story about pirates and children who can fly. Barrie was very aware of the scientific developments of his day and the original Peter Pan stories are infused with ideas about man’s place in the natural world and the mental lives of children and animals. In many places Barrie seems to have anticipated ideas in cognitive psychology that only emerged after his death.

CDF: I wonder why a respected neuroscientist came to write a book about Peter Pan?

ppkgcoverRMR: I came across an early edition of Barrie’s first Peter Pan book ‘Peter Pan in Kensington Gardens’, written in 1906. In the text I found descriptions of many aspects of cognitive psychology that have only been studied scientifically since the middle of the twentieth century. The more I read, the more I found. I was hooked.

CDF: Most people are unaware that Barrie wrote two novels about Peter Pan in addition to the pantomime. Do these give us a different view of the nature of Peter Pan and the intentions of Barrie?

Continue reading Cognition and Consciousness in Peter Pan

RMR: In ‘Peter Pan in Kensington Gardens’, Peter is about a week old while in ‘Peter and Wendy’ (1911), which is based on the pantomime, he is about six or seven years old (although he supposedly ‘still had all his baby teeth’ which indicates his immaturity). Although Peter is ‘the boy who wouldn’t grow up’ he undergoes several changes of age, out of synchrony with other people in the stories. One explanation for this is that Peter is Barrie’s memories of himself as a child, achieved through ‘mental time travel’, and that Barrie is both exploring the nature of childhood and re-living his own childhood.

CDF: What was Barrie like?

RMR: Barrie was a lonely man who had had a difficult childhood and a childless marriage that ended in divorce. He found adults difficult and sought refuge in a fantasy world outside the normal stream of consciousness of our mundane existence.

CDF: And yet, he was also one of the most successful authors of his time and knew everyone from Thomas Hardy to A. A. Milne. But he certainly had problems. I believe that Barrie suffered from insomnia, as did Lewis Carrol,  but that Barrie attempted to control this by taking heroin. He must often have experienced the strange states of consciousness that can occur at the borders of sleeping and waking. Did these experiences inspire some aspects of the Pater Pan story?

RMR: Yes, Barrie complained of terrible sleep and gave accurate descriptions of almost all the clinical parasomnias in his stories. It is more than likely that he experienced these sleep disturbances and that this taught him that what he experienced and what was happening ‘out there’ are not the same thing. When Barrie was six years old his older brother drowned. Their mother became very depressed and Barrie felt that his dead brother was more real in his mother’s mind than he was. This may have encouraged Barrie to think in terms of internal mental states rather than the outside world.

CDF: Barrie seems to have been seeking a special state of heightened consciousness, which he believed people experienced in some historical or childish Golden Age.

You call this state ‘sublime consciousness’. What is this?

RMR: Although he didn’t use these terms, Barrie clearly understood the modern distinction between primary mental representation (mainly perception) and secondary representation (mainly episodic memory, anticipation of the future, and the imagination of alternatives). His stories were based on the notion that these were different, mutually exclusive, types of consciousness and that only adult humans had what we would now call ‘secondary representation’. He longed for a pure type of primary consciousness (which is what I called sublime consciousness) which he believed was available to animals, children and only occasionally to adults. Barrie argued that animals and very young children were not burdened with the ‘sense of time’ or ‘sense of agency’ that comes with the development of secondary representation and so were free to enjoy a heightened experience of the present.

CDF: This reminds me of work showing that, if you think about being happy, you will feel less happy.

But isn’t there one animal in the stories who does have secondary representation?

2-solomons-sockRMR: Yes, Solomon the crow. In the picture by Arthur Rackham we see him with the sock he is using to save for his pension. Crows have always had a reputation for being clever and Nicky Clayton has published work suggesting that they can plan for the future.

CDF: And, crows’ brains contain more neurons than the brains of some monkeys of comparable size.

I remember the rather sentimental episode in the pantomime where children are told that every time they say, ‘I don’t believe in fairies’, then a fairy will die. But, in your book, you suggest that Barrie is making a comparison between the type of thing that fairies are and the type of thing that money is.

RMR: Well, yes, Barrie liked to play tricks with words and ideas. He made ethereal objects behave like solid objects; a shadow, for example, is folded up and put in a drawer. Like Lewis Carroll, Barrie saw that words and the objects they represented were separable but, whereas Carroll adopted a semantic view that ‘a word… means just what I choose it to mean’. Barrie took a more pragmatic approach in making Wendy describe a ‘kiss’ as a ‘thimble’ when she could see that Peter was using the two words the wrong way round. Barrie then goes on to distinguish between solid objects and socially constructed objects. In a rather complex scene, Peter has forgotten how to fly and is marooned on the island in the Long Water in Kensington Gardens. A boat made out of a five pound note washes up on the island, but, rather than using the boat to make his escape, Peter cuts the bank note up into smaller pieces and uses these to pay the thrushes (who have been told that these ‘coins’ are valuable) to build him a bird’s nest boat. Here Barrie recognised that money is not only a piece of paper, but is also a socially constructed object that only exists as currency so long as everyone believes in it. Similarly, fairies are socially constructed objects, who only exist if you and your friends believe in them.

CDF: We once did an imaging study where people watched bank notes being torn up. The higher the value, the more brain activity we saw.

You suggest that a major theme of the Peter Pan stories concerns the cognitive differences between animals, children and adults. After Darwin published his theory of evolution, people had to reconsider these differences, since he had shown that we are all animals.

RMR: Peter Pan is described as a ‘betwixt-and-between’,
part child, part bird (he can fly) and part instinctive, slightly dangerous creature, like the god Pan. This allowed Barrie to compare the mental world of adults, children and animals and to consider the extent to which human behaviour is instinctive rather than rational and enculturated. These are very post-Darwinian themes and Barrie clearly believed that children start life with animal instincts and develop additional, specifically human cognitive skills as they mature. This reflects the view put forward by the nineteenth century embryologist, Ernst Haeckel, that ‘ontogeny recapitulates phylogeny. It would not have occurred to anyone before Darwin to compare the behaviour, especially the moral behaviour, of humans and animals because humans were made in the image of God and animals were just dumb beasts. Barrie also refers to paths in Kensington Gardens that have been made by men and adjacent ‘vagrant paths that have made themselves’ suggesting that he understood that evolution could apply to anything that was based on bottom-up processes, not just plants and animals.

CDF: One of the more exciting research programmes to emerge toward the end of the 20th century was about theory of mind or mentalising. This is the ability that enables us to realise that other people may have different beliefs from us and that it is those beliefs, rather than reality, that will determine their behaviour. Children don’t seem to acquire a full version of this ability until they are about 6 or 7 years old.

RMR: Although Barrie does not specifically name the nature of Peter’s cognitive limitations, his various descriptions of Peter’s behaviour certainly indicate failures of mentalising. Peter cannot remember events of the past and cannot understand what ‘afraid’ means because it is about the future. Peter also appears not to have a fully developed theory of mind and the social cognition that develops from it. He has great difficulty dealing with the beliefs and desires of others.

“What are your exact feelings for me?”
“Those of a devoted son, Wendy.”
“I thought so,” She said, and went and sat by herself at the extreme end of the room.
“You are so queer,” he said, frankly puzzled, “and Tiger Lily is just the same. There is something she wants to be to me, but she says it is not my mother.”
“No, indeed it is not,” Wendy replied with frightful emphasis.

Here Peter is clearly described as not knowing what it is that Tiger Lily wants to be to him, rather than not knowing how he should respond to her amorous advances. Later Peter gives a puzzled, nervous laugh and skips off merrily when he thinks that Wendy has been shot dead.

CDF: Well, it’s certainly amazing that Barrie was so much ahead of his time in presenting these various ideas, which we associate with contemporary cognitive psychology, but is this enough? What does your foray into the humanities contribute to contemporary neuropsychology?

RMR: Barrie was a close observer of human and animal behaviour as well as being extremely well read. I suspect that many of his astute observations were entirely his own but the implications of scientific discovery was a very pressing issue amongst the intelligentsia of the time and Barrie knew a great deal about science. For example, his story of the fairy duke who does not know that he is in love charmingly demonstrates the James/Lange theory of emotion, which was proposed at the end of the nineteenth century. At first I was surprised by the cognitive approach he adopted but I now realise that much early psychology, especially that proposed by William James (whom Barrie had met), was very cognitive in approach. But it was then overshadowed by the subsequent schools of Psychoanalysis and Behaviourism. We should pay much more attention to the psychological insights of the nineteenth and early twentieth century.


Barrie’s literature makes science accessible, but Barrie also argued that a good grounding in science and the scientific approach could contribute to literature when he said ‘science is the surest means of teaching you how to know what you mean’.

Photograph of the paths in Kensington Gardens courtesy of Harry Baker
A version of this conversation previously appeared in The Psychologist, January 2017

Time we identified cognitive phenotypes for the social deficits in autism

Social deficits? Their not the same as everyday difficulties in social situations. We all have experienced such difficulties, because the social world has as much potential for suffering as for happiness. But when we talk of social deficits in autism it’s about not being quite part of the social world. Yet, it’s not about deliberately withdrawing from this world and not about being antisocial.

I am not starting at the behavioural level to define the social deficits in autism. I would get lost in a maze where cause and effect can hardly be distinguished. For instance, there are people who often feel rejected, while others find them unbearably aggressive. Which comes first, the rejection or the aggression?


Continue reading Time we identified cognitive phenotypes for the social deficits in autism

Behaviour is determined by so many factors that a glitch in just one of these factors is incredibly hard to discover. It’s like being in the midst of climate change and generally rising temperatures, while being confounded by a cool summer. Like the observed cool temperatures, observed behaviour is potentially misleading if we want to learn something about what causes the behaviour.

Therefore I am starting at the cognitive level. I will only later go to the behavioural level when I know what signs to look out for. At the cognitive level I can let my thoughts range freely around the imagined mental machinery. I would like to poke into different bits and take them apart. I would like to see what would happen if a particular piece were missing or not working properly. Would the projected outcome resemble the real social problems that are experienced by autistic people?

What parts? What mental machinery? Well, its just a metaphor, and it may be better to talk of apps, perhaps. But here are some ideas. I believe evolution has endowed us from birth with a number of gadgets and these enable us to become the social creatures that we are. When any of them goes wrong, social deficits should result, – not to be confused with everyday social difficulties.

If we can find clues to the gadgets and what can go wrong, we are on the way to discover their neural basis and eventually their genetic origin. Progress! But how many are there? Can they each go wrong, separately or together? Here I am speculating and limit myself to 7 hypothetical mechanisms. Lets call them start-up kits, since they are subject to learning and development.


Start-up kits for a thoroughly social human being

  • Agency recognition (prey, predator, mate, friend, enemy
  • Affiliation (recognising kin, bonding, attachment)
  • Alignment (mimicry, resonance, contagion)
  • Belonging (identity, trust, loyalty, ingroup/outgroup distinction)
  • Hierarchy (knowing one’s place, dominance/submission, alliances)
  • Mentalising (mental state tracking, persuasion, deception, reputation)
  • Morality (fairness, equity, altruism, punishment)

I imagine these start-up kits run on the fuel of social emotions to regulate social behaviour (think guilt, shame, jealousy, pride, contempt). They depend on other social signals too, as displayed in eye gaze, voice and body language. For my money, its the last two, mentalising and morality, that have some claim for being uniquely human and being shaped by cultural learning. They also have some claim  for being broken in autism.

Perhaps any of the 7 mechanisms can be broken in autism. Perhaps this leads to different forms of social deficits and hence different cognitive phenotypes. This would go some way to explain the heterogeneity of the autism spectrum. It might also explain different degrees of severity – the more the worse, obviously. Perhaps testing different mechanisms separately would lead us to form subgroups in the autism spectrum. As far as I know this has not been done in any systematic way.

If they’re not broken, these hypothetical mechanisms work spontaneously and effortlessly, and are active throughout an individual’s life. This is reminiscent of instincts. They respond to a certain set of stimuli with a certain set of flexible responses. However, the responses can be suppressed or modified via conscious control.

To what extent these mechanisms are independent , or interacting with each other, is a matter for debate. If they were separate then, when one of them wasn’t working, a ‘hole’ in the mental architecture would appear, but the rest might function well. Do holes matter? It depends. Compensatory learning is a wonderful thing. If it works then the hole can be covered up to make it almost invisible in behaviour.

How then do you identify cognitive phenotypes?  You need to devise behavioural tests to capture the hypothesised cognitive deficit. Sadly, we don’t have the tests. This is not because they are impossible to design, but because nobody has made the necessary major effort to devise a systematic battery of tests that are reliable and sensitive.

Most of the tests we have so far give you a score that estimates a level of performance, but they don’t tell how that score was achieved. We need tests that can do precisely that. Moreover, we need to be able to detect how a score was achieved. It could be low, because of fatigue. It could be high, because of compensatory training. So, constructing valid and reliable tests is not a trivial task, they need a lot of man power and, of course, funding.  I expect this is why we haven’t got them yet..

All the experimental tests we have at present are precarious. This is why I am not impressed when somebody tells me that, on tests in the lab, their autistic child is no different from any typically developing child, and hence there is no difference in underlying mental architecture. I think it would be beautiful to discover autism specific architecture, a whole city of familiar, yet different, structures.Urville18


Image credits:

Tup Wanders Flickr creative commons                                                          Chris Frith                                                                                                                                                            Gilles Trehin, Urville



The Encounter

Over the last couple of years, Uta & I have been meeting with Simon McBurney, director of Complicite as he prepared for his one-man show, The Encounter. Simon hoped that we might be able to tell him what neuroscience can reveal about the nature of consciousness.

The Encounter dramatizes the experiences of Loren McIntyre, as described in Amazon Beaming by Petru Popescu. When Simon told us about this book it was long out of print, but we managed to find a second hand copy. As a result of Simon’s work it was republished in 2015.

Loren McIntyre was a National Geographic photographer, and this is the story about his experiences when he was lost in the remote Amazon rain forest. His survival depends on the leader of a small group of Mayoruna people who he has followed into the jungle and then become hopelessly lost. But there is no common language through which they can communicate. He feels utterly isolated with ‘a psychological distance of 20,000 years’ between him and the people who are his only hope finding a way back. Eventually he starts to experience ‘communication’ from the leader of the group when he sits near him. He begins to understand some puzzling behaviour, for example, why the group keep destroying their villages and moving on. Remarkably, this communication doesn’t depend on language.

McBurneyIn The Encounter everyone in the audience wears earphones, which helps Simon to recreate and share all the strangeness and terror of McIntyre’s experiences through the wonder of acoustic technology.

When we first talked to Simon about the work he was developing around Amazon Beaming, he asked us whether we thought it was possible for two people to communicate without words. We said, absolutely.

And here is why.

Continue reading The Encounter

Communication is not simply about the transfer of information. You can do that with a cash machine. When we communicate we know that we are communicating, and we know that our partner knows that she is communicating. We have a subjective, conscious experience of communicating. This experience, we hypothesise, predates language.

This is what I would have said in a discussion planned after a performance of The Encounter at the Barbican. Unfortunately I couldn’t be there because I had to have an operation for a detached retina.

What is conscious experience?

When I look out into the audience, I am aware of innumerable faces. I have the subjective experience of seeing many faces. But this is an illusion. I don’t mean that you are all figments of my imagination. I am confident you are all out there, but, even so, some of you at least are figments of my imagination.

The problem is that my contact with you all seems so direct, when it is really very slight. The only clues I have about you come from the sparse signals that my eyes and ears are sending to my brain. From these crude signals, and from years of experience, my brain can make quite a good model of what’s out there.

elephantYou will remember the story of the blind men who come across an elephant. One feels its trunk and thinks it is a snake, another feels its leg and thinks it is a tree.

A single sighted man who comes across an elephant is doing the same thing. The elephant is too big to see with a single fixation of the eye. We have to look all over it. If our eye lands on the trunk, then it’s a good bet that it’s a snake. But, then, as the eye moves along it a head or a tail should appear. When this doesn’t happen, then the model has to be changed. It isn’t a snake. Perhaps it’s an elephant. The more evidence our eyes take in the more plausible it becomes that the thing is an elephant. Our eyes move very fast (4 to 8 fixations per second). Within a few 100 msecs we see the elephant. We are entirely unaware of all the work our brain has done and, of course, what we are seeing is not the elephant, but the model that our brain has constructed. This model is often incomplete with several missing bits that are filled in with guesses. This is why some of you are figments of my imagination. There is a well known youtube video, showing that a gorilla can walk by some basketball players without being noticed, if you are too busy counting the basketball passes.

But what is the point of all this vivid subjective experience?

HuxleyCapTH Huxley believed that our conscious experience has no function: ’Consciousness [is]completely without any power of modifying the working [of the body] as the steam-whistle which accompanies the work of a locomotive engine is without influence upon its machinery.’ I believe that Huxley was wrong and we can see this from the metaphor he chose. This is because the steam-whistle does influence the behaviour of other engines.

Our conscious experience is very vivid, but also very private. There is no way I can have your experiences. It even is possible that the colour experience that I call red is actually the one you would call green if you were to experience it. How could we ever know? But there is a paradox here. Our conscious experience may be private, but it is also the only aspect of our mental life that we can share with others. I can’t tell you anything about what my brain is doing. And I certainly can’t tell you about all those mental processes that never reach my consciousness.



What I can tell you about is my model of the world. And, at the same time, you can be telling me about your model of the world. So if we are like steam locomotives, we are certainly hearing each other’s whistles.




Conscious experience is for interacting

And, because we are sharing the same world and because we also have very similar brains, our models are also likely to be very similar. But they will not be entirely similar. Our models will also depend on all our past experiences including our interactions with others. Our models of the world will be strongly influenced by our cultural background.

But what happens when two people interact? Interacting with another person is different from interacting with a rock. Unlike a rock, the person I am interacting with is creating a model of me at the same time as I am making a model of her. The model I create of you helps me to predict what you are going to do, which also helps me to communicate with you. My model of you will have many different aspects. I will try to discover what sort of person you are. But in my view the most important aspect of you that I am trying to model, is your model of the world. That is the model of the world we are currently sharing.

brainsBecause we are sharing the same world, any differences in our models will reflect our different experiences and cultural backgrounds. So, when I know something about your model, I know something about you. But, if I need to communicate with you, then I should try to make my model similar to yours. And, at the same time, you will be trying to make your model similar to mine. Some believe that, if two devices interact while making inferences about each other, then they will eventually converge on the same model.

Language is extremely useful for discovering something about other peoples’ models of the world, but it is not the only way. Simply by watching how someone moves you can learn about how they see and understand the world about them. The more you spend time with someone else, the better you will get at predicting how they are going to move. You won’t know how you do it. It just happens.

To make this prediction you have learned about their model of the world and, inevitably, this has changed your own model. At some point the two models will be in almost perfect synchrony. At this point you will have the conscious experience of what seems like, and, indeed is, wordless communication.

Putting language into the social brain

cartoon@langBlogChris and I are visitors at the Interacting Minds Centre at Aarhus University during August and September 2014.  This is a great opportunity to meet people who excel at providing stimulating conversation on “What makes us social”.  Admittedly I am more of a talker than a listener, and I assume that talking is completely, utterly, super-important in interactions. So why do social neuroscientists not pay more attention to language? Continue reading Putting language into the social brain

Kristian Tylen is the person I turned to with my burning question: What is the role of language? When we consider social interactions this almost always involves language. Is language actually the primary driver of our social interactions, or is it the other way round?

KT:  Language is multimodal. It probably started with gestures and this presupposed social interaction of a kind. There are different theories about the evolution of language and there is actually no real consensus.

UF: That’s what I felt when I recently read Stephen Levinson’s review  of two new books on the evolution of language, one by Derek Bickerton and one by Michael Tomasello.

KT: These represent interestingly different theories and there are others too. There is the view that language should be seen as completely separate from social communication, and that it grows from its own cognitive mechanisms. I sort of doubt this. I think language is primarily for the use of communication and it evolved as a tool to improve communication.

UF: Without specifically referring to Chomsky, what do you think about an innate predisposition for language in humans?

KT: It depends on what you mean by innate. My preference is to think that language both evolves from and is shaped by our interactions with the surrounding physical and social environment.  And so it is out there rather than inside us. This is demonstrated by the way that language structures are motivated. Take the way we talk about pitch  In English and Danish: We talk about low and high pitch mapping onto low and high spatial notation. Other languages for instance use thick and thin or big and small. These relations all map onto universal experience. Low tones come from big creatures and high tones from small creatures. And it turns out that it is very difficult to learn the opposite relations.

UF: But things out there need to act on the brain, no?  I don’t disagree with you that the world outside the mind is a starting point, but the experience of the outside shaped the inside, over millenia.  As a consequence, I guess there are some pre-shaped circuits in the brain, which might become obsolete, if  the environment changed radically.  So this is why I would put the outside in second place, and the inside first.

KT: So what do you mean by innate?

UF: I use the word for neural circuits that have a long evolutionary history. I don’t use innate to mean present at birth, and I don’t use it to mean that learning is not required. But I believe the circuits are preprogrammed for certain types of learning to be facilitated. That is why I like to talk of start-up kits rather than innate circuits. Start-up kits lead to effortless fast learning. No start-up kits require effortful slow learning.

KT: For me, it’s important to remember that the driver of evolutionary history is the environment, and this rather puts anything innate in second place. I am not very comfortable with putting too much stress on the inside of humans. Communication happens because we share the same experiences and systems on the outside and can create symbols that are mutually understood almost irrespective of our individual insides.

UF: Here is my naïve sketch of a likely scenario for the evolution of language in human beings, as opposed to other species. I want to speculate on what might be an innate start-up kit, still requiring learning, and what might not be innate and can only be gained by learning.

Chris, who meanwhile did the sensible thing of googling ‘evolution of language’, weighed in with a devastating remark:  You might be interested to know that the Linguistic Society of Paris in 1866 banned any debate on the topic as unsuitable for study because of the lack of empirical evidence.

UF: Too bad. I will still tell my story. I have only just made it up!  And what you are saying means that It cannot be worse than any other current proposals. They’re all speculation.

In the beginning was not the word. In the beginning there were two things: a start-up kit for spontaneous vocalisations, and another for spontaneous mentalising. These innate mechanisms are visible in precisely located and well connected neural circuits in the brain. They evolved separately, growing from already existing capacities in our remote ancestors.

KT: What were these pre-existing capacities?

UF: I speculate that even very remote ancestors had vocalisations, and they had the experience of agency. They must have had this to distinguish prey and predator and behave accordingly.

My story requires a third thing, and it demands a sufficiently complex brain. This is combining language and mentalising. This is not trivial. I imagine it needed many generations of our ancestors inventing words and telling each other what they mean, influencing each others minds along the way. Now for the magic bit: Language and mentalising put together enhanced each of their effects. This third thing is perhaps primarily responsible for the rise of human culture.

CDF: Mike Tomasello made a similar but different proposal. He believes that the ability to cooperate is a uniquely human driver of language and of culture.

UF: But what underlies the ability to cooperate in the way humans do? I would guess it depends on mentalising. I find it hard to conceptualise cooperation, or joint attention for that matter, as a more primary mechanism than mentalising. Cooperation and joint attention are not so much cognitive mechanisms as behaviours. No doubt cooperation is an important driver of culture, but so is probably competition. We cooperate within groups but compete with other groups.

KT: Why not? It’s a ‘just so story’ as always happens when people talk about evolution.

CDF: I think the Linguistic Society of Paris had the right idea.

Our conversation ended, but here are some details  that I would have given to bolster up my argument – if I had had the chance.

1. Spontaneous vocalisation. These have a useful instrumental purpose, like the warning cries that initiate flight from predators, or the high pitched cries that bind mothers and babies. This is a mechanism present in many mammal brains and presumably present in human ancestors as well. However, as Stephen Levinson reminds us in his review, the vocal apparatus of human beings is immensely complex and is under voluntary control, which may not be the case in many other animals. Speech is a complex motor action and well localized in the brain. Voice actions and hand gestures have similar requirements in terms of motor programmes and syntax. The FOXP2 gene has been associated with such actions and their relevance to speech and motor disorders has been documented.

2. Spontaneous mentalising. I find it very interesting that Martin & Santos have shown that the monkey brain can represent another’s viewpoint, but not another’s belief. Only the latter counts as mentalising, and Agnes Kovacs and her colleagues observed this in 7 months old babies. There are many other advantages, such as friendship, and also some disadvantages, such as deception. Apparently, there are forms of friendship and deception present in monkeys, but typically as rare examples. It is easy to see how language can scale up both advantages and disadvantages.

3. The third thing – two together. I am speculating that one of the two mechanisms on its own would probably bring you up to the level of a three-year old child. Not bad, but not enough to get on with the business of creating lasting and cumulative culture. Culture, as we all know depends on learning from others.  The specifically human form of learning from others which involves teaching is likely to be dependent on mentalising, but it would be a poor vehicle for learning without language.  Humans use language not just to make others do something, but also to express their mental states and to appeal to another’s mental state. Humans have done very well by learning from each other through the use of language. After many thousands of years humans got to a point where language was turned into literacy, and then science and technology started to take off.

Of course there are alternative views

How to be smart

Are humans the smartest species? What does it mean to be smart?

CDF: I am very interested in your suggestion that we should think about specific packages of behaviour for different species that are determined, to some degree, by their environmental niche. This brings me to a question I have often thought about. We often assume that humans differ from other species simply because we are smarter. But what do we mean by smart? Perhaps I can anticipate your answer: What is smart in one niche might be foolish in another. For example, we assume that being able to delay gratification (not eating the marshmallow immediately) is smart, but it would be very foolish in a volatile environment where no one can be trusted.

Continue reading How to be smart

RR: Being smart must include surviving and producing surviving offspring – just think about the opposite.

CDF: In this sense, in the long run, bacteria will turn out to be far smarter than humans.

RR: There is more to being smart: we usually mean something specifically cognitive. Evolution involves adaptation but in a stable environment this can lead to specialization that becomes maladaptive when the environment changes. Being large may be advantageous because it means you may be able to overwhelm your enemies. But the package of being large means you take a long time to grow, produce a few offspring that need looking after and therefore you need to live a long time. This makes your species vulnerable to environmental fluctuations. Bacteria are smart because they reproduce very quickly and can adapt rapidly to environmental change. So, in the battle between antibiotic-wielding humans and bacteria, the bacteria tend to win. The mega-fauna did well in a stable environment, but do not cope well with human-induced environmental change and many will soon be extinct.

UF: I am glad that we are not giants.

RR: Humans are not giants, but they are mega-fauna. They are exceptionally successful as mega-fauna because their best adaptation is adaptability itself. Humans have adapted, behaviourally, to many different terrains and climates and have changed the terrain to suit themselves. They have also changed the climate, but haven’t quite adapted to that yet.

SmartTestSo it is cognitive and behavioural flexibility that makes humans smart. Cognitive flexibility allows humans to learn a lot which makes them even more behaviourally flexible and therefore even smarter.


UF: How on earth did humans evolve to have this adaptability? Can you briefly sketch out how this might have happened?

RR: We need to talk about selection and the Baldwin Effect.

This describes the way that learned products of cognitive flexibility  – good survival tricks – become genetically determined in a species by selection, rather than by inheritance of acquired characteristics. Here is an example: When proto-humans increased their communication skills as proto-speech, individuals with useful cognitive apps in this new social environment e.g. being good at remembering the order of sounds, being good at hearing inflections, would be favoured. This goes on over many generations and eventually a large collection of language-useful apps would be embedded in the human brain.

Now as to the mechanisms involved – this is complicated. We have to consider what genes do. Genes always compete against their alternative alleles and never do anything for the good of the species. But genes have the products of other genes, in their own body and other bodies, as part of their environment, such that complex competitions and co-operations will develop between genes. Picture how different personality types may win or lose depending on the environment. Sometimes pessimists survive catastrophe, and sometimes optimists advantageously exploit opportunities.  So a mixture of different cognitive styles (think collections of cognitive apps) will exist in a population in an equilibrium, which will fluctuate with environmental events.

Being a lot smarter than other people has survival value but it has one obvious disadvantage; in a social species being different can be difficult.


Acknowledgements: ‘Culture-fair test’ modified Danish cartoon, source unknown; ‘Leaps & Bounds’, Punch Magazine vol 4 p 273 June 10th 1893

Are bees better than humans?

To distract me from dangerous goings-on outside my window, where men are cutting down tall trees, Chris & Uta have asked me about the social lives of marmosets. This is not really altruism on their part. They will use the information for their book.

CDF: We want to know about the origins of human social cognition. Where should we look? Bees and ants? Other primates?

Continue reading Are bees better than humans?

RR: I think you need to look at all and any species and work out the packages of behaviour that different species use.

UF: What do you mean by packages of behaviour?

RR: Behaviour, and social structure, depend on the constraints of environment and evolution and both boil down to reproductive success. Does the species have to get through a cold winter? Does the species live up trees? It is factors like these that will determine whether the species produces a large number of offspring with low parental investment or a low number of offspring with high parental investment. These strategies come as packages and much social structure follows therefrom.

UF: So, is reproductive behaviour, mating and nurturing the young, at the biological root of social behaviour?

RR: This is where we find differences between species, because of the constraints I just mentioned. Old World monkeys tend to have a hierarchical mating system. Here males compete with other males for access to large numbers of females – though it all gets complicated with alliances and pay-offs. New World monkeys tend to live in more or less monogamous families – though it all gets complicated with adultery and incest. New World monkeys tend to live up trees, like birds, which are also usually monogamous so perhaps trees matter.

UF: Are humans more similar in their mating strategy to New World monkeys?

RR: Humans exhibit different strategies in different societies depending on food supply and other external threats. We can infer a lot about Human ancestral social behaviour by the fact that males are slightly bigger than females. This size difference occurs in any species where males compete with other males for resources and for females. The ultimate aim here is to win wars, get rid of other males, and acquire as many available females as possible. Of course, the size difference in humans is not large compared to the difference in some species. This implies a long history of more family based behavioural packages as well.

UF: Mike Tomasello’s lab has a vast number of studies comparing the joint interactions of great apes and those that happen between human children. There are similarities, but one of the main differences seems to be that, while human social interactions are basically cooperative, those of chimpanzees, gorillas and orang-utan’s are mostly driven by competition. Tomasello’s conclusion is that great apes are extremely limited in their cooperative capacities, and this is their essential difference to humans.

CDF: But unlike chimpanzees, Marmosets seem to be extremely cooperative, showing, for example, cooperative breeding. Is this true?

marmosets RR: Kin selection explains many aspects of superficially altruistic behaviour. Co-operative breeding in marmosets usually means assisting in the rearing of the offspring of relatives because of the family structure of groups of marmosets. But an owner of a captive breeding colony of marmosets will often attempt to cross foster a neonate when the breeding female of one family has had just one baby and the breeding female of another family has just had triplets. This is often successful because the family can’t be sure that the newcomer is not related to them (and marmosets aren’t very good at counting either). In the wild, quite a large troop will contain mainly related animals. So a certain amount of general co-operation could be sustained by kin selection.

Several additional explanations have been put forward to explain co-operative behaviour in co-operative breeding species such as marmosets. These are all plausible, but none are truly altruistic since they increase the reproductive success or survival of the protagonist.

* Helpers that have cared for other infants have greater reproductive success when they become parents than individuals that do not have previous infant care experience. This is undoubtedly the case for marmosets.

* Unrelated helpers can gain the benefits of living in a social group, such as communal foraging or protection against predators. This requires the unrelated individual to be accepted by the group and this usually only occurs when the incomer arrives as a potential breeding partner.

* Males that display involvement with infants are more likely to obtain subsequent mating with the female they assist. This is unlikely since the male is usually assisting in the rearing of his own offspring (so has access to the dominant female) or his own sibs. The dominant female suppresses ovulation in her daughters and thereby prevents incest in the rest of the family.  “No hanky-panky please.”

UF: Social learning is something that happens in almost all animal species. It seems possible to us that this learning has shown a sort of step change in evolution in humans. This is to do with learning by deliberate teaching, a two-way process. Is this plausible? How would evolution explain such a step change?

RR: The difficulty in getting a hand-reared orphan animal to be accepted by, mate with and rear offspring with, members of their own species shows how important social learning is for survival. Evolution will favour parents who behave in such a way that offspring learn social behaviours. In New World monkey species, the fathers and older siblings contribute to the rearing of the next litter and, in captivity, offspring reared alone by just their mother are rarely able to rear offspring themselves. The difference between ‘behaving in such a way that learning in offspring occurs’ and ‘teaching offspring’ is one of intention by the parent and so the step change (if there is one) will lie in the evolution of several cognitive ‘apps’, e.g. ‘appreciation of the existence of the future’, such that intentions can develop. New ‘apps’ have emergent functions made from the amalgamation of smaller ‘apps’.

UF: I love your use of the term ‘app’ for a special cognitive adaptation!

CDF: The importance of learning by teaching is that it offers a mechanism for culture to accumulate over generations. Culture seems to be the one specialised niche for humans.

RR:  Intentionality will always speed up cultural development, but animals have cultures too. Diet and food-finding practices are cultural in that they differ between groups of the same species.

The trees are down now! Good. I can go out again.

CDF & UF: Thank you, Ros. We’ll be back and quiz you more about processes in the evolution of behaviour.

Photo acknowledgement: