Chimpanzee shows ability for foresight and deceiption
When you walk into the Vandalur zoo, one of the first animals you meet is the Chimpanzee. Thanks to their striking similarity to humans, many visitors stand trasnsfixed wondering whether these animals too think like us. While some may deny that, and others might think it is obvious, science is yet to have its last word on this debate. A new study suggest that those who think it is obvious that the Chimpanzees too think like us, might not be very much off the mark.
The chimpanzee Santino, from Sweden, shot into limelight when a study was published in 2009, that suggested that it had the ability to plan for future events. The study showed that the chimp was collecting objects, like stones, and keeping them in store, so that he can hurl them at visitors.
But it was hard to establish, if the chimpanzee was indeed planning for the future. What if he was just collecting stones for some other purpose, but when he saw the visitors, realized that he could use the same stones at the visitors too.
A new study published in PLoS one, an open access journal, on May 11th 2012 titled “Spontaneous Innovation for Future Deception in a Male Chimpanzee”, went one step further in giving chimpanzees the benefit of doubt on whether they have foresight or not. In the 2009 study, it was observed that the pile of objects was visible to all, and every time he was about to send one from his collection flying at a visitor, he would precede it with an aggressive display.
Zookeepers spotted this hint and started warning visitors to back off, as soon as the chimpanzee put on its aggressive display. This time around, the chimpanzee acted smarter. He learnt to avoid giving such a cue to the zookeeper, by not displaying his aggression before throwing. In one instance, he took two objects, held it in a hand, and walked slowly towards the visitors. On the way, he also casually picked up an apple lying down, and put it in its mouth. When he came close enough, he threw the stones suddenly at the visitors without any warning.
Moreover, he also started storing his ammunition in places the visitors cannot see, like behind a rock or behind a log. Such concealment did not stop with naturally available hiding places. Santino also covered up the visible piles with hay brought in from a different place.
“By combining his old strategy of gathering projectiles in advance with his new strategy of concealment and behavioural inhibition, he could extend his ability to throw stones at visitors from close range” says the study.
But the authors are cautious enough not to attribute a theory of mind, the ability of an individual to think of what another individual could be thinking, to Santino yet. “What the behaviour does appear to show is that the chimpanzee is able to predict the behavioural responses of others not present at the time of the prediction”, the authors write.
Reference: Osvath M, Karvonen E (2012) Spontaneous Innovation for Future Deception in a Male Chimpanzee. PLoS ONE 7(5): e36782. doi:10.1371/journal.pone.0036782. A PDF of the paper can be downloaded from this link.