This article originally appeared in issue 2 of Metric Magazine, June 2013.
“I wanna be like you” – culture, tool use and higher order thinking in non-human animals
By Jessica Law
Is nothing sacred anymore?!
Making and using tools, developing different cultures and thinking about thinking itself were for a long time defining characteristics of humans. But one by one we have been stripped of these titles by impudent upstarts in the animal world. On March the 15th this year, a brown bear was observed for the very first time using a barnacle-covered stone to “scrub” its face. Sparrows with regional accents and baboons that can apparently second-guess one another have redefined the traits we consider human. So is there anything that truly separates us from the animal world? If so, what? And if not, where does that leave us?
Getting inside the minds of animals is one of Biology’s most daunting tasks. Even if they do display similar behaviour to us, how do we know that the same thought processes are behind it? Are they using conscious thought, instinct or simply learning by rote? D.J. Chalmers of the Scientific American put it perfectly: science consists of “Easy Problems” and “Hard Problems”. The Easy Problems – how nerves are wired, how genes build bodies – can be studied and measured by known scientific methods. But the means by which a mass of neurones bring about conscious thought is still as unclear as it was to Darwin’s associate Huxley: “as unaccountable as the appearance of Djin when Aladdin rubbed his lamp”.
But Biologists aren’t put off that easily. Much can be learned by observing different animal cultures. These occur when “societies” within the same species exhibit different behaviours, which are passed on by learning, rather than genes.
The most extreme example is chimpanzee societies, where 39 possible cultural differences have been observed. Some societies fish for termites with sticks, while others crush nuts with stone “hammers” and “anvils”, sometimes even employing a stone wedge to stabilise the anvil. These hints at “ratcheting”: an idea passed down the generations is built upon at each step until a product is reached that no single chimpanzee could achieve in its own lifetime.
When learning, juvenile chimps choose which adults to observe. But to imitate their actions exactly would involve putting themselves in their teacher’s place. This requires higher order reasoning: the ability to speculate about another animal’s mental state.
Hamydaras Baboons seem to exhibit such thought processes. In their strongly hierarchical societies, a female in the dominant male’s harem will only groom a subordinate male if he is hidden by a rock. This implies that the female knows the dominant male can’t see the subordinate. But this behaviour may simply have been learned by trial and error. More solid experiments were needed.
In one trial, a dominant and a subordinate chimpanzee were presented with two bananas in an enclosure. The dominant could only see one (the other was hidden by a block), but the subordinate could see both. In 73% of the trials, when the doors opened, the subordinate rushed to grab the food behind the block first: the one he knew the other chimp couldn’t see.
This sounds pretty conclusive, but the subordinate may simply have been reading subtle clues in the dominant’s behaviour. It may have noticed the dominant looking at the visible food for longer, and responded accordingly.
In another trial, blue jays were seen to project their own experiences onto others. They were allowed to hide wax moth larvae in sand. If they saw they were being spied on by another bird, only the jays who had stolen food in the past would re-hide their own. For naïve jays who had never pilfered another bird’s hoard, the idea didn’t even cross their minds!
But again, logic forces us reassess. The jays that re-hid their food may simply have learned to observe other birds as a result of their pilfering experience. We humans tend to use our own higher order reasoning to assume other species have it. But until we find more reliable evidence, we must avoid adding extra layers of meaning to an observation when a simpler explanation would suffice.
It would seem plausible that some animals do have a theory of mind. It would be far easier for an animal to learn one overriding concept than hundreds of sets of individual rules acquired by trial and error. But until advances in brain imaging and neurology turn the Hard Problem of consciousness into an Easy Problem, we can only speculate.
Charles Darwin said: “the difference between man and the higher animals, great as it is, is certainly one of degree and not of kind”. Although the scale and complexity of human behaviour has not yet found an equal in the natural world, there is no clear dividing line between humans and animals. Complacency is no longer an option (according to Galen, my chimp PA, who is typing this up as I speak).