I’ve always been fascinated by tip-of-the-tongue moments. It’s estimated that, on average, people have a tip-of-the-tongue moment at least once a week. Perhaps it occurs when you run into an old acquaintance whose name you can’t remember, although you know that it begins with the letter “J.” Or perhaps you struggle to recall the title of a recent movie, even though you can describe the plot in perfect detail.
What’s interesting about this mental hiccup is that, even though the mind can’t remember the information, it’s convinced that it knows it, which is why we devote so many mental resources to trying to recover the missing word. (This is a universal experience: The vast majority of languages, from Afrikaans to Hindi to Arabic, even rely on tongue metaphors to describe the tip-of-the-tongue moment.) But here’s the mystery: If we’ve forgotten a person’s name, then why are we so convinced that we remember it? What does it mean to know something without being able to access it?
The larger question is how the mind decides what to think about. After all, if we really don’t know the name – it’s nowhere inside our head – then it’s a waste of time trying to find it. This is where metacognition, or thinking about thinking, comes in handy. At any given moment, we automatically monitor the flux of thoughts, emotions and errata flowing in the stream of consciousness. As a result, when a name goes missing we immediately analyze the likelihood of being able to remember it. Do we know the first letter of the name? Can we remember other facts about the person? Are we able to remember the first names of other acquaintances from high school? Based on the answer to these questions, we can then make an informed guess about whether or not it’s worth trying to retrieve the misplaced memory.
Interestingly, a new experiment with a variety of primates (gorillas, chimpanzees, bonobos and orangutans) demonstrated that great apes also demonstrate some rudimentary metacognitive skills. The study, conducted by Josep Call at the Max Planck Institute for Evolutionary Anthropology, involved presenting the primates with two hollow tubes. One of the tubes came with a food reward, while the other was empty. The apes were then observed as they searched for the reward.
In the first condition, the apes were given no visual information but were allowed to listen as the tubes were shaken. In the second condition, the apes were shown the location of the food – they watched the tube get baited – but were then kept away from the tubes for different lengths of time. Call wanted to see if forgetting the location of the food would lead to a lengthier search, just like people persisting when trying to remember a name on the tip-of-the-tongue. In the final condition, Call varied the quality of the food reward, as he wanted to see if the apes would search harder for a more valuable treat.
Sure enough, the apes demonstrated an impressive amount of mental flexibility when searching for the food. For instance, they were much more likely to check inside the tubes after a long period of time had elapsed since they’d been shown the location of the treat. Because they were convinced that they knew where the food was even though they couldn’t remember its exact location – it was like a name on the tip-of-their-tongue – they were more likely to search for the reward. The looking didn’t seem futile. (The apes were also much more likely to search for more valuable treats.)
As Call concludes: “The current results indicate that the looking response appears to be a function of at least three factors: the cost of looking inside the tube, the value of the reward and the state of the information. The combination of these three factors creates an information processing system that possesses complexity, flexibility and control, three of the features of metacognition.”
I wonder how far this experimental paradigm can be taken. Does a dog search longer in the backyard for a bigger bone? If so, is Fido practicing metacognition? My childhood cat was the laziest creature in the world. But she was willing to rummage around the recycling bin for hours searching for the empty tuna can. Did she posses the same metacognitive qualities as those chimps spending more time looking for the tastier treat?
The moral, though, is that even the loftiest of human talents, such as the ability to reflect on our own thoughts, have plenty of animal precursors. We’re so much less special than we like to imagine.