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.
Are we humans simply remodelled apes? Chimps with a tweak? Is the difference between our genomes so minuscule it justifies the argument that our cognition and behaviour must also differ from chimps by barely a whisker? If “chimps are us” should we grant them human rights? Or is this one of the biggest fallacies in the study of evolution? NOT A CHIMP argues that these similarities have been grossly over-exaggerated - we should keep chimps at arm’s length. Are humans cognitively unique after all?
Friday, 14 May 2010
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:
Background
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.
Methods
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.
Conclusion
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.
Background
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.
Methods
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.
Conclusion
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.