Orangutans can talk about the past
Now, the ability to discuss what happened yesterday or last week, is a subtle but really important cornerstone of language. But we don’t know when or how this ability to react to something historical came about. But this week scientists announced they’ve discovered that one of our closest relatives also has this ability; Georgia Mills has been to the jungle to hear which one…
Georgia - If you went down to the jungles of deepest darkest Sumatra what might you see? A sun bear, a pygmy elephant or perhaps a scientist crawling around under a stripy blanket pretending to be a tiger. That's exactly what Adriano Lameira and his team at the University of St. Andrews were doing but I promise you there is a reason. They were trying to find out more about perhaps Sumatra’s most famous inhabitant and our close cousin the orangutan.
Adriano - I am looking at orangutan calls as living models of the precursor system of language. Language fundamentally transformed how our species transmits information and knowledge. But we have very little clues of how did this happen. How did such a new powerful system emerge within our own lineage? Orangutans provide a really interesting case where we can go back and use their vocal behaviour as models for what may have happened within our own lineage.
Georgia - So, Adriano and his team went on a fact finding mission to Borneo and Sumatra to find out what kinds of calls the orangutans make. But there's only one problem, orangutans aren't all that chatty.
Adriano - I've spent many days with the microphone over my head waiting for them to say something and I would go back to camp with no recording to speak of.
Georgia - What to do? The team had an idea. What if they could get them to make an alarm call by showing them what appeared to be one of their predators like a tiger or a leopard.
Adriano - Yeah, so typically it was me walking on all fours and then we had sheets covering and then it was the pattern of the sheets that differed between different types of predator that we wanted to simulate. You know I was the lead author so I had to take the example role.
Georgia - The things you do for science.
Adriano - Exactly.
Georgia - And this disguise apparently seemed to work. The orangutans behaved nervously climbing away and urinating. But…
Adriano - But we were not getting any vocal responses, which was confusing at first. To our surprise it was only minutes later up to 20 minutes later actually that the female started to engage in vocal responses. So we immediately knew that there was something odd about the whole situation.
Georgia - So why wait for minutes before making a distress call?
Adriano - You wouldn't want to respond in the presence of the tiger and therefore incur the risk of an attack at that moment. On the other hand, because they could have simply remained silent forever, otherwise the infant would have never properly understood that what just happened was a dangerous event and so they are waiting to be in safety to inform their infants about the danger.
Georgia - What does this, the fact that they're delaying their calls, what does this tell us about orangutans?
Adriano - So far there is this saying that animals typically communicate while being stuck in the present. What this shows us is that they actually can disassociate this and therefore communicate the information about something that is not happening in the here and the now and this is a characterizing feature of language across all the world's languages. We are constantly speaking of things that are not here or now. So this characterises language and yet there were so far no examples in mammals or within the primate order.
Georgia - Right, so you are saying this is a kind of a really important stepping stone in the advance of language to be able to talk about things that aren't what's right in front of us right now.
Adriano - Absolutely I think it really becomes powerful because the information that you can start actually reporting on in transmitting really expands in all directions, right, because then you can refer to things in the past you can refer to things into the future and so to cross these threshold is terribly important and I think we really start to have a lot of the ingredients that we see in language coming together within one of our ancestral lineages and now we can really start seeing how they may have interacted and therefore how could they have past that threshold and really started something that we could potentially call a proto-language, a system that really became the forerunner of language.