One of the defining traits of humanity is conciousness or “sapience.” Arguably it’s what separates us from the beasts, so understanding its development is of prime importance when examining human evolution. To identify the origin of concious thought is to identify the very origin of humanity.
However, answering such a deep question is hampered by the fact we don’t really have a clue what conciousness is. There’s no decent biological definition out there, making the study of its evolution somewhat problematic. And by problematic I mean nigh impossible.
So instead scientists tried to identify aspects of conciousness they could define and pin down, so they could study those instead. Because as much as they love a good mystery, sometimes they just have to say “screw it” and study a question that actually has an answer.
One of such competent of conciousness that was identified and defined is the “theory of mind” (shortened to “ToM” by experts and lazy people). ToM is essentially the ability an individual has to understand that another has different thoughts, feelings, knowledge, intention etc. than they do.
In other words, it’s the understanding that what goes on in another’s head is different to what goes on in our own. Although that might seem like a fairly basic skill we might take for granted it is actually rather complex and is something children don’t learn until they’re around 5 years old and seems to form the foundation of much of their higher reasoning – even conciousness, perhaps.
Here we run into our second major problem in the study of conciousness: bones don’t preserve thoughts. The material remains left behind by our ancestors offer no real insight into their thoughts, including their thoughts regarding what other people thought.
So instead we have to look at living animals, in particular chimps. The logic here being that if chimps do it and humans do it then our common ancestor also likely did it and we both retained that behaviour from them.
It’s at this point some raise the objection that there is too much evolution between us and chimps for them to be studied in this manner. We’ve both been evolving independently for 7 million years, after all. However, given that chimps and our ancestors had a similar brain, any inferences made about intelligence (including ToM) should be reasonably valid.
This prompted many experiments to determine if chimps had a ToM. The results of these typically showed that chimps could understand another chimp sees and intends to do different things than they do, but it was unknown if they knew this because they worked it out with a ToM or just read the other individuals body language.
However, recent research purports to have finally determined that chimps do in fact have a ToM. They made model snakes and left them lying around where chimps would find them. This scared whoever discovered it, often prompting them to warn the others in their group.
Crucially, they were more likely to warn others with these “alert hoos” (Researcher: “I’m a scientist, I have better things to do than think of creative names”) if the chimps they were warning had no clue that the snake had been seen.
If they spotted the snake and hollered, they would be less likely to warn others again if they had heard their previous shout. They would be even less likely if the other chimps had seen the snake. However, if new chimps arrived who had not heard or seen anything, they would give another “alert hoo” and warn them.
They made more alert hoos if there were family or children nearby but whether or not they started calling was primarily influenced by the knowledge of other chimps, finally demonstrating they have at least a basic ToM.
Or at least it would if there was more data. Don’t get me wrong, it’s well thought out and well executed research but it’s only studying one group of chimps. That means they can’t demonstrate this isn’t simply a cultural phenomenon (yes chimps have culture), with chimps in this group learning to give alert hoos if, for example, new individuals arrive. Further research on other groups is needed.
Research has been circling around a chimp ToM for so long it’s frustrating. The wealth of evidence that goes so close to proving it to me suggests they do in fact have a ToM even if no single study is definitive.
But, alas, that confirming study is needed before we can say that chimps (and by extension our ancestors) do have a theory of mind – a fundamental foundation of conciousness – with confidence.
|Crockford C, Wittig RM, Mundry R, & Zuberbühler K (2011). Wild Chimpanzees Inform Ignorant Group Members of Danger. Current biology : CB PMID: 22209531|
|Perner, J., & Lang, B. (1999). Development of theory of mind and executive control Trends in Cognitive Sciences, 3 (9), 337-344 DOI: 10.1016/S1364-6613(99)01362-5|
|Woodruff DS (1999). Chimp cultural diversity. Science (New York, N.Y.), 285 (5429) PMID: 10454930|