Thursday 19 August 2010

Orang-utans are not remotely like humans

Experts should know better than to claim that great apes can communicate in a similar way to human beings.

Time and again, we are told that humans are not that special after all: abilities previously thought to be uniquely human are now purportedly evident amongst the great apes. The most recent claim, published in the current issue of the Royal Society journal Biology Letters, is that orang-utans use mime to make themselves understood.

‘Given pantomime’s sophisticated attributes, some consider it to be uniquely human’, the article’s authors, Anne Russon and Kristin Andrews, write. ‘Pantomime is gesture in which meaning is acted out; in humans, it can be as simple as twirling a finger to indicate a vortex or as complex as telling the Ramayana.’

The researchers analysed 20 years of data on previously captive orang-utans now living in the forest in Indonesian Borneo. They identified 18 cases of pantomime, 14 of which were addressed to humans and four to other orang-utans.

One example, we are told, involved an orang-utan reminiscing through miming a past event. A female orang-utan named Kikan had injured her foot the previous week and a member of staff had used a fig leaf to seal the wound. This first-aid was apparently re-enacted by Kikan. Russon said: ‘She’s not asking for anything, which is the most common aim observed of great ape communication, but appears simply to be sharing a memory with the person who helped her when she hurt her foot.’

There is no doubt that apes and other animals are able to communicate with each other in the wild – whether through courtship rituals, dominance and territorial displays, or food and alarm calls. For instance, dogs bare their teeth and growl to signal to other animals to leave their territory. Cats try to look bigger and more menacing by puffing out the hair on their tails to signal to other animals not to oppose them. Subordinate chimpanzees use grunts directed to dominant chimpanzees to signal appeasement or submission. However, these are instinctive communications. The evidence for any animal being able to communicate intentionally – let alone ‘be able to make sense of their world by telling stories, and to relay their thoughts about the world to others’ as Andrews claims - is still non-existent.

Michael Tomasello, author of a number of fascinating books, including Origins of Human Communication, who has spent many years studying the abilities of great apes at the Wolfgang Köhler Primate Research Center in Leipzig, tells me: ‘Without some kind of control observations we cannot be sure what [the orang-utans] are doing.’ For instance, ‘How often do the orang-utans make those hand movements in other, irrelevant contexts?’, he asks.

The fact is that we do not know whether Kikan was trying to communicate her gratitude - or any other meaning - or whether she was merely making some random hand movements.

As I argue in my new book, Just Another Ape?, one needs to go beyond first impressions and anecdotal evidence in order to establish the differences, and the alleged similarities, between human beings and the great apes. The researchers’ identification and description of a set of behaviours could be interpreted in a number of different ways. And even if there was evidence that some of the behaviours served a communicative function, we do not know whether this communication was intentional or not.

Daniel Povinelli, former director of the Cognitive Evolution Group at the University of Louisiana at Lafayette, who has carried out some groundbreaking research to compare and contrast how humans and chimpanzees understand the world around them, tells me that the apes may merely have been emitting random behaviours. ‘[Emit] a random behaviour. If you are reinforced, stop. If more of what you want is still available, repeat the behaviour that was reinforced. If it’s all gone, stop. If you do not get what you want, [emit] a different random behaviour. If nothing you want is present, do nothing.’

It is sloppy simply to identify and describe a particular behaviour - or set of behaviours - and conclude that this is evidence of animals being able intentionally to convey meanings to other beings. Even if the set of behaviours was shown to serve a communicative function, it does not mean that the ape was communicating intentionally: it may be the result of random behaviours or instinctive communications.

Take the example of vervet monkeys. Groundbreaking research by Robert Seyfarth and Dorothy Cheney in the 1980s on vervet monkeys in the wild showed a seemingly sophisticated method of communicating about the proximity of predators. Living on the edge of the savannah, vervet monkeys have many predators. Their chance of survival would therefore be greatly increased if they were able to respond appropriately to different vocal warnings. Indeed, it was found that the vervets have specific alarm calls for specific predators: the alarm call for an eagle is different from that for a leopard, which in turn is different from that for a python.

From the outset of their study, Seyfarth and Cheney stressed that it could not be established from these initial findings whether the callers vocalised with the explicit intent of referring to the proximity of a predator. They were careful to point out that there was no evidence that the monkeys had ‘thoughts’ that they intentionally conveyed to others – such as ‘Oh no! I see a dangerous leopard. I had better warn the others quickly and make sure that they know it is a predator that may get us unless we seek safety in a tree.’

In fact, further research shows that the caller’s vocalisations are not ‘intended’ for other animals. In Origins of Human Communications, Tomasello demonstrates that the alarm calls primarily benefits the caller – by, for instance, distracting the predator – and that the other vervets are merely informed by ‘eavesdropping’. This was demonstrated by Cheney and Seyfarth in follow-up experiments where vervet mothers would see ‘predators’ approaching their offspring. The mothers would not give the alarm calls unless they themselves were at risk.

In The Language Instinct, evolutionary psychologist Steven Pinker persuasively takes apart many of the ‘preposterous’ claims made about apes’ and other animals’ language abilities. He stresses that we all have a tendency to anthropomorphise – thinking that animals are capable of a lot more than they are in reality. ‘People who spend a lot of time with animals are prone to developing indulgent attitudes about their powers of communication’, he writes, giving the example of his great-aunt Bella who ‘insisted in all sincerity that her Siamese cat Rusty understood English’. But we should expect more of those involved in ape language studies. They should be prepared to evaluate critically the data from their studies. Instead, many of the claims of those involved in ape language studies are not much more scientific than those of his great-aunt, Pinker argues. I would extend that criticism to Russon and Andrews.

For instance, in the research paper they claim that one female orang-utan acted out events in order to help her make sense of her experience. She ‘re-enacted her activities with her partner after deliberately turning her back on him, probably to understand them’, they write. How on earth can we know that this is what the ape was doing? Another example is the so-called evidence of an adolescent male ‘pantomiming a request’. He picked a leaf and a stem in front of a human staff member and ‘with eye to eye contact, wiped dirt off his forehead with the leaf then gave the leaf to [the human] to request that she do the same.’ (1) But we cannot know that this is what he was ‘requesting’. He may merely have been randomly passing the leaf to the human.

Ape communications are incomparable with human language. We debate and discuss ideas, construct arguments – drawing on past experiences and imagining future possibilities – in order to change the opinions of others. We pantomime. We create everything from great literature to nursery rhymes that help us make sense of the human condition, and we can pass this on down the generations: some nursery rhymes have survived centuries. We can communicate an infinite number of meanings and develop an infinite number of arguments. We can debate and discuss everything from international politics and economics to the most mundane issues.

I cannot see even the remotest comparison between the beauty, power and complexity of human language and an ape wiping its forehead with a leaf and passing it to another being.