Click on the cover to link to OUP's e-catalogue then turn to the biology section.

Interview Podcast with George Miller

Interview Podcast with George Miller
Click on the pic to link to the NOT A CHIMP podcast on Blackwell's Website

Preface to "Not A Chimp: The Hunt For The Genes That Make Us Human"

In many ways, this book is born out of frustration for a professional career in popular science television where ideas about comparative primate cognition, and the similarities and differences between us and our primate relatives, have continually circled me but constantly evaded my grasp in terms of the opportunity to transform them into science documentary. On the plus side, keeping a watching brief for over a quarter of a century on subjects like comparative animal cognition and evolution allows you to watch a great deal of water flow under the bridge. Fashions come and fashions go - specifically, perspectives on the similarity - or otherwise - of human and ape minds.

I remember the first Horizon science documentary about the chimpanzee Washoe, the great ape communicator, using American Sign Language to bridge the species barrier. And, later, Kanzi the bonobo jabbing his lexicon. These were the apes, as Sue Savage-Rumbaugh has put it, that were "on the brink of the human mind".

I remember when the pre-print of Machiavellian Intelligence, by Andrew Whiten and Dick Byrne, plopped onto the doormat of the BBC Antenna science series office in 1988. Suddenly primatology had become a great deal more exciting. Could primates, and especially higher primates like chimpanzees, really be as full of guile, as dastardly, as cunning, and as manipulative as the eponymous Florentine politician? Could they really reach deep into the minds of other individuals to see what they believed and what they wanted, and turn that information into deception?

I remember discussing primate cognition with a young Danny Povinelli, as we sat finger-feeding ourselves shrimp gumbo and new potatoes out of plastic Tupperware containers in a Lafayette restaurant surrounded by an alligator-infested moat, before returning to his kingdom - the New Iberia Research Centre - where the University of Louisiana had lured him back to his native deep South by turning a chimpanzee breeding centre for medical laboratory fodder into a primate cognition laboratory with one of the largest groups of captive chimpanzees in the country. He looked like a kid who had just been thrown the keys to the tuck shop.

In those days Povinelli shared the zeitgeist - spread by Whiten's and Byrne's work, and started by Nick Humphrey and Alison Jolly before them - that, since the most exacting and potentially treacherous environment faced by chimpanzees and other primates was not physical, but the social environment of their peers, they had evolved a form of social cognition very much like our own, in order to deal with it. This was further elaborated into a full-blown "social brain" hypothesis by Robin Dunbar, who related brain neocortex size to social group size throughout the primates and up to man. Povinelli's early work reflects this optimism for the mental life of apes, but both ape-language and ape-cognition research was subjected to a cold douche of searching criticism during the 1990s, and misgivings set in regarding the effectiveness of the experiments that had been constructed to guage ape cognition. Now the worm has turned again, with a number of research groups emerging with bolder and bolder claims for the Machiavellian machinations of primate minds, only to be powerfully countered by the curmudgeonly skepticism, chiefly by Povinelli, that these researchers are merely projecting their mental life onto that of their subjects; that, rather in the frustrating manner of Zeno's arrow that could never quite reach its target because it continually halved its distance to it, no experiment constructed thus far can actually get inside the mind of a chimp and show us exactly what it does and doesn't know, or how much, about the minds of others or the way the physical world works. One influential part of the world of comparative animal cognition talks of a continuum between ape and human minds and shrinks the cognitive distance between us and chimps to almost negligible proportions, while another returns us to the unfashionable idea that human cognition is unique, among the primates, after all.

When I began writing this book the working title was "The 1.6% that makes us human". My aim had always been to scrutinize the impression put about in the popular science media that humans and chimps differ by a mere 1.6% in our genetic code - or even less - and that it therefore makes complete sense that this minuscule genetic difference translates into equally small differences in cognition and behaviour between apes and man. However, contemporary genome science and technology, over the last few years, have dramatically advanced the power and resolution with which scientists can investigate genomes, eclipsing the earlier days of genomic investigation that gave rise to the "1.6% mantra".

As with comparative cognitive studies, conclusions on chimp-human similarity and difference in genome research depend crucially on perspective. To look at the complete set of human chromosomes, side by side with chimpanzee chromosomes, at the level of resolution of a powerful light microscope, for instance, is to be overwhelmed by the similarity between them. Overwhelmed with a sense of how close our kinship is with the other great apes. True, our chromosome 2 is a combination of two chimp chromosomes - giving humans a complement of 23 chromosome pairs to 24 in chimps, gorillas and orang-utans - but even here you can see exactly where the two chimp chromosomes have fused to produce one. The banding patterns you visualize by staining the chromosomes match up with astonishing similarity - and that banding similarity extends to many of the other chromosomes in the two genomes. However, look at a recent map of the chromosomes of chimps and humans, aligned side by side, produced by researchers who have mapped all inversions - end-on-end flips of large chunks of DNA - and the chromosomes are all but blotted out by a blizzard of red lines denoting inverted sequence. Now you become overwhelmed by how much structural change has occurred between the two genomes in just 6 million years. True, not all inversions result in changes in the working of genes - but many do - and inversions might even have been responsible for the initial divergence of chimp ancestor from human ancestor.

The extent to which you estimate the difference between chimp and human genomes depends entirely on where you look and how deeply. Modern genomics technology has led us deep into the mine that is the genome and has uncovered an extraordinary range of genetic mechanisms, many of which have one thing in common. They operate to promote variability - they amplify differences between individuals in one species. We now know, for instance, that each human is less genetically identical to anyone else than we thought only three years ago. When we compare human genomes to chimpanzee genomes these mechanisms magnify genetic distance still further. I have tried, in this book, to follow in the footsteps of these genome scientists as they dig deeper and deeper into the "Aladdin's Cave" of the genome. At times the going gets difficult. Scientists, like any explorers, are prone to taking wrong turnings, getting trapped in thickets, and covering hard ground, before breaking through into new insights. I hope that those of you who recoil from genetics with all the visceral horror with which many regard the sport of pot-holing will steel yourselves and follow me as far as I have dared to go into Aladdin's Cave. For only then will you see the riches within and begin to appreciate, as I have, just how limited popular accounts of human-chimpanzee genetic difference really are. Let me try and persuade you that this is a journey, if a little arduous at times, that is well worth taking.

There are a number of scientists around the world who have the breadth and the vision to have begun the task of rolling genetics, comparative animal cognition, and neuroscience into a comprehensive new approach to the study of human nature and this is part, at least, of their story. They strive to describe the nature of humans in terms of the extent to which we are genuinely different to chimpanzees and the other great apes. Somehow, over 6 million years, we humans evolved from something that probably resembled a chimpanzee (though we cannot yet be entirely sure) and the answer to our evolution has to lie in a growing number of structural changes in our genome, versus that of the chimpanzee, that have led to the evolution of a large number of genes that have, effectively, re-designed our brains and led to our advanced and peculiar human cognition.

If you don't believe me, hand this book to your nearest friendly chimpanzee and see what he makes of it!

Friday, 14 May 2010

And Now - Empathic Ravens!

Over the last couple of weeks we have been besieged by a number of articles trying to persuade us that chimps show enormous empathy and signs of distress over the dead. Always, such displays of emotion are held to be further proof - if proof were needed - that chimps are incredibly closely related to us, and share much, if not all, cognition with us. Now comes this paper by raven-enthusiast Thomas Bugnyar and his colleague, Orliath Fraser, suggesting that ravens who are uninvolved bystanders to an act of aggression are capable of displays of "post-conflict affiliation" to the victim or loser. The victim invariably shares a more rewarding relationship with the bystander than the bystander does with the aggressor. The researchers rule out the interpretation that bystanders acted thus to reduce the chance that they would also be attacked - the victims of re-directed aggression. They point out that, in the many cases where such behaviour has been noted in chimps, there has never been any mention of the victim soliciting bystander affiliation and that the victim raven invariably directs such solicitation toward those bystanders with which it shares a strong relationship - perhaps to reduce the chance that it will be attacked again.

But is it "consolation" which implies a degree of emotional concern - empathy? The authors believe so because the affiliation is more likely to occur after a severe "dust up" where the victim appears to be in some clear distress. Furthermore, at the risk of contradicting some earlier statements, they maintain that, in some cases, consolers, or would-be consolers, were attacked by the former aggressor - implying that "consolation" is not without risk and therefore is a case of altruism. Ravens, unlike rooks which have a long-lasting pair-bond social structure, live for much of their lives in more loosely related non-breeding communities, and therefore form patterns of valuable relationships with a number of individuals.

All very interesting stuff but I cannot help feeling queasy about the use of such loaded terms as "consolation", "empathy" and "altruism" to describe these behaviours. They are no more acceptable in descriptions of raven social behaviour than they are in, for instance, Frans de Waal's descriptions of post-conflict affiliation and "concern" in chimps. However, the important thing to note is that such behaviour is not the exclusive province of a near-related primate. It is shared by a bird and, as such, cannot be used, tiresomely, to underscore the evolutionary proximity between us and chimps. The behaviour has its roots in similarities between the social complexity of ravens and chimps not their cognitive or genetic proximity to humans.

Do Chimpazees Learn By Imitation Or Emulation?

How best to explain the ability of chimps to learn simple technologies from each other? It is clear that such social learning occurs and is very powerful but do the same processes hold for both humans and chimpanzees? A number of important experiments over recent years suggest that humans actually over-imitate, even at the risk of copying irrelevant detail, and that this is extremely important the more complex, and therefore opaque, the task being demonstrated is. Here Claudio Tennie, Josep Call and Mike Tomasello, of the Max Planck Institute in Leipzig, present results of a so-called "floating peanut" task which showed that chimps learned with the same amount of success whether they were shown the correct solution to the task in a literal sense, or another method which achieved the same result. Emulation, they conclude, may be enough to explain the social transfer of skills. Here is the abstract. PLoS is free, so anyone interested can download the entire paper:


It is still unclear which observational learning mechanisms underlie the transmission of difficult problem-solving skills in chimpanzees. In particular, two different mechanisms have been proposed: imitation and emulation. Previous studies have largely failed to control for social factors when these mechanisms were targeted.

In an attempt to resolve the existing discrepancies, we adopted the ‘floating peanut task’, in which subjects need to spit water into a tube until it is sufficiently full for floating peanuts to be grasped. In a previous study only a few chimpanzees were able to invent the necessary solution (and they either did so in their first trials or never). Here we compared success levels in baseline tests with two experimental conditions that followed: 1) A full model condition to test whether social demonstrations would be effective, and 2) A social emulation control condition, in which a human experimenter poured water from a bottle into the tube, to test whether results information alone (present in both experimental conditions) would also induce successes. Crucially, we controlled for social factors in both experimental conditions. Both types of demonstrations significantly increased successful spitting, with no differences between demonstration types. We also found that younger subjects were more likely to succeed than older ones. Our analysis showed that mere order effects could not explain our results.

The full demonstration condition (which potentially offers additional information to observers, in the form of actions), induced no more successes than the emulation condition. Hence, emulation learning could explain the success in both conditions. This finding has broad implications for the interpretation of chimpanzee traditions, for which emulation learning may perhaps suffice.

Disagreement Over Role Of Mirror Neurons In Autism

Marco Iacoboni and Mirella Dapretta have long held that a defective mirror neuron system in the brains of autistics explains their relative inability to register social cues like emotional expressions. Their measurements have backed that up. However, Ilan Dinstein, of the Weizmann Institute in Israel, as Ewen Callaway reports in this New Scientist piece, begs to differ. He compared autistics and normal individuals in an fMRI scanner while they viewed either repetitive hand movements or a variety of hand movements. Excitation of the mirror neuron system declined with exposure to the repetitive stimulus in both autistics and controls. Perhaps general brain "noise" is the answer to autistic disability, he argues. Iacoboni and Dapretta apparently are worried about the small sample size in Dinstein's experiment and claim the jury is still out.