Nature 395, 656 - 657 (1998)
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Are talkers the only thinkers?
KARENMCCOMB1 AND STUARTSEMPLE2
1Karen McComb is in the Laboratory of Experimental Psychology, School of Biological Sciences, University of Sussex Brighton BN1 9QG UK
2Stuart Semple is at the Institute of Zoology, Regents Park London NW1 4RY UK
If a Lion Could Talk: Animal Intelligence and the Evolution of Consciousness
by Stephen Budiansky
Free Press: 1998. pp.219 $25
Buster Keaton and comrades in The Doughboys: is our understanding of animal intelligence distorted by anthropomorphism?
"One chimp was alone in the feeding area and was going to be fed bananas. A metal box was opened electrically from a distance. Just at the moment when the box was opened, another chimp approached at the border of the clearing. The first chimp quickly closed the metal box and walked away several metres, sat down and looked around as if nothing had happened. The second chimp left the feeding area again, but as soon as he was out of sight, he hid behind a tree and peered at the individual in the feeding area. As soon as that individual approached and opened the metal box again, the hiding individual approached, replaced the other and ate the bananas."
This intriguing observation of the Gombe chimpanzees by Frans Plooij (Whiten, A., Byrne, R. W. Primate Report 27, 99, 1990) can be interpreted in two very different ways. Perhaps the chimpanzee that hid himself was capable of attributing a mental state — the intention to deceive — to his social companion and made use of this information in order to outwit him. Alternatively, as an extremely astute observer, he could simply have learnt by trial and error that this intricate pattern of behaviour was likely to secure him a reward.
The problem of distinguishing between these two sorts of explanation is by no means trivial and it applies to almost every study in which behaviour is used to assess the nature of the animal mind.
Budiansky is therefore right to explore in depth the feats of "unthinking intelligence" that associative learning can potentially produce, and to examine how this process may underlie behaviours which initially suggest sophisticated reasoning on the part of the animals involved. To his credit, he does this lucidly and with a wealth of examples drawn from throughout the animal kingdom. He also highlights the important fact that cross-species comparisons of mental abilities are often biased towards species that have inherent predispositions to learn how to perform the laboratory tests involved. This point is particularly salient given the relative ease with which certain primates adapt to interacting with humans in the laboratory and to performing tests that involve elements of manual dexterity.
In light of these problems, how does Budiansky address the central issue of the book — the question of whether animals are capable of 'conscious' thought? His attempts to do this are seriously hampered by the fact that he never provides us with a clear definition of what he considers 'consciousness' to be. One infers as the book unfolds that consciousness, for him, involves second order intentionality (in Daniel Dennett's sense) — the ability to have thoughts about thoughts. First order intentionality, the ability to have thoughts in the first place, is not sufficient.
But Budiansky goes further than this. He appears slavishly caught in the stance that the only mechanism through which conscious reasoning can occur is human language, which he believes "is so intimately tied to consciousness that the two seem inseparable". This obviously excludes the possibility that animals could have non-verbal thoughts about thoughts, a dangerous assumption given that studies on human infants suggest that elements of second order intentionality can in fact occur in the absence of language.
The conclusion from Budiansky's viewpoint can only be that animals, lacking the linguistic abilities of humans, aren't conscious.
What, then, are we to make of evidence that a variety of primates use representational alarm calls to denote specific classes of predator; that species as wide-ranging as African grey parrots, bottlenosed dolphins and pygmy chimpanzees readily adapt to using acoustic or visual labels to represent external objects and events; that rhesus monkeys can represent the ordinal position of objects in arbitrary lists; or that vervet monkeys have representations for certain sorts of social relationships?
At one point Budiansky admits that "the question of what a mental representation is lies at the heart of the mystery of animal thinking and consciousness". But direct discussion of this issue in the light of findings that animals do appear to use mental representations is sadly lacking. This can only partly be attributed to Budiansky's reluctance to accept the results of these studies. Although he dismisses evidence for representational alarm calls (even though their existence is widely accepted by experts in the field) and is singularly unimpressed by the achievements of lexigram-trained apes, he does consider that vervet monkeys "have no trouble spontaneously mastering mental representations of social relationships" and that "monkeys really have an ability to store items in sequence and mentally run through and draw conclusions from such a sequential list". It is frustrating that Budiansky simply seems unwilling to examine the full implications of these rudimentary abilities to mentally code information on things external to self.
Given the nature of Budiansky's approach it is perhaps unsurprising that he should advocate abandoning studies of animal consciousness, in favour of investigating things that animals "are good at". His judgements about what animals should be good at — "things they have evolved to do to survive in their particular ecological niche" — seem to be extremely limited. For example, he appears willing to include under this umbrella abilities for hiding and recovering food but not a capacity for counting, even though social animals such as lions can and do benefit from accurately assessing the number of opponents that they face in territorial disputes. He also fails to appreciate that the complex social environment in which many animals live would be likely to exert strong selective pressures for the evolution of an ability to attribute mental states. In particular, the far greater predictive power afforded by reading the minds of others rather than simply their behaviour would provide a much more effective means for individuals to outmanoeuvre social competitors.
It is Budiansky's strongly stated belief that our motivation for studying consciousness is biased by an anthropocentric view of the world. Perhaps this is why he feels that one should not seek human-like abilities, such as the understanding of mental states, in animals. However, this conclusion is unjustified. The question of whether any species other than our own can appreciate that it is possible to manipulate minds as well as behaviour is no mere anthropocentric indulgence — instead it is one of the most important and challenging issues in social evolution.
In light of his convictions about the inextricable link between consciousness and language, it is probably no coincidence that Budiansky's book is called If a Lion Could Talk.Indeed, he suggests that if a lion couldtalk "his mind would no longer be a lion's mind". The fact that an animal cannot talk should not, however, be taken to indicate that it lacks consciousness — it is absolutely crucial not to prejudge the issue. Unfortunately, Budiansky appears to have done just this.
Even if consciousness is equated to second-order intentionality as Budiansky proposes, the problems of finding appropriate methods to discern whether animals can attribute a mental state to others are not insurmountable. Although animals lack our language, their understanding of the intentions and knowledge of others could still be examined if more imaginative experimental paradigms were employed. The techniques used to monitor the development of mental state attribution in human infants are potentially very promising in this respect.
It is disappointing that, far from suggesting new directions the study of animal consciousness could take, Budiansky actively discourages further research in this fascinating area.