Lecture Topic: Primate Behaviour - IELTS Listening Answers & Explanations

Good morning; today's lecture will be about primate behaviour. Up until now I've talked mostly about physical features: how they apply to living primates; how we use them for classification; how they apply to the fossil record. But human evolution isn't simply about how we've changed physically over the last 70 million years; it's also about how our behaviour has changed.

Now, if I asked you to define what is meant by the term "human", you could probably, hopefully, give me a list of characteristics that physically define us. But at a philosophical level, I would hope that what you'd be really proud of is not that we normally walk on two legs, but that we can reason and imagine. Descartes put it succinctly: "I think, therefore I am" although, admittedly, not quite in this context.

This lecture isn't about human behaviour per se, but about primate behaviour in general, and animal behaviour too, since just as we can use the physical characteristics of living primates to give us clues and insights into the physical characteristics of human ancestors, so we hope that the behaviours of non-human primates will be similarly enlightening for the behaviour of our ancestors.

To begin, let's talk a bit about primate cognitive abilities. I don't want to mention a lot of different behaviours without first mentioning cognition. Cognition is the amount of thought that goes into a behaviour. There is a world of difference between an animal hitting a nut with a rock and cracking it by accident, and an animal thinking to itself: "I can't bite into this nut. I know, I need something to use as a hammer to crack it." However, it can be very difficult coming up with experiments to differentiate these two.

We can easily test mental skills, such as recall and discrimination, using methods such as the Wisconsin general test apparatus and various training experiments. But it's much harder to work out the degree of thought required. This is still a big problem in evaluating the status of great apes. Just how nearly "sentient" are they? Sentient, for those of you who don't remember, means there is the presence of conscious thought.

There are various behaviours that could be seen to support the presence of conscious thought in primates. Various sorts of altruism, or helping others without directly benefiting, can be found in certain great apes. The animals team up to achieve various goals: for example, hunting, in chimps. This would seem to require a degree of cognition. Another feature that has come to light recently is "Machiavellian intelligence". Work, especially with baboons, seems to indicate that there is a lot of deliberate social deception going on: sneaky mating; passing the blame onto others; using infants for defence. At first glance, this seems very complicated behaviourally, but again, it can, just about, be explained in a fairly minimally cognitive way. Highly trained chimps, such as the signing chimp, Washoe, and the computer-aided communication of Kanzi also indicate a high level of intelligence. An interesting fact is that these language-trained chimps do much better in the standardised intelligence tests too, indicating that we probably underestimate primate intelligence in our traditional experiments. It seems that primates are not all that interested in the colour of pencils; they want to know the latest gossip about their friends - sound familiar?

And of course, cognition and intelligence in primates is a thorny problem, with deep moral and political ramifications.