Do you know the feeling when you’ve been struggling with something for ages and suddenly the solution dawns on you?
What you’ve just done constitutes insight, the ability to use a mental representation of a problem and draw on past experience and knowledge to solve it. Are humans the only species that can do this? And if animals can do this, how can we tell?
Social species, such as primates, toothed whales, and elephants, tend to have bigger brains than non-social species. There are a lot of pressures for social living – you are competing for food with members of your species, but at the same time need to maintain relationships with those same individuals. This requires a bigger memory to keep track of your dealings with other individuals.
A big advantage of living in social groups is that you are surrounded by potential experts who know more about some things than you do. Individuals can benefit from “social learning”, and many of them follow the gaze of others and benefit from watching what others do.
The social or Machiavellian intelligence hypothesis predicts that social species will have bigger brains and particularly bigger neocortices. This is generally true, but does not explain the vast cognitive leap to great apes and humans in particular.
Perhaps the difference lies not in social but in physical cognition, how animals understand their physical environment. Many animals, including the above social species as well as corvids, are able to recognise the geometry of what another individual can see from a different location than themselves. Species that cache food not only remember where they hid the food, but for how long it has been hidden and can predict whether it’s spoiled. Primates plan their foraging to wait until previously unripe fruit has had time to ripen.
These elaborate abilities show a physical understanding of the world, but can be generated by simple cognitive rules without relying on insight.
On top of these abilities, great apes do something extraordinary. They perform complex food-processing, the best example of which is nettle-eating by gorillas.
We take for granted our manual and digit “role differentiation” (the ability to do different things with each hand and each finger, respectively), but great apes are the only family with this ability. Gorillas use their manual dexterity to perform complex folding of nettle leaves in order to eat them.
This behaviour is not linear, but hierarchical –the important steps must occur all in the same order, but the way to get between them is not straightforward and there is individual variation in the minor details.
Gorillas learn this complex behaviour by imitation, which requires “behaviour parsing”, the ability to watch a behaviour and break it into constituent parts. Young gorillas watch their mothers folding nettles for a long time, so that they are quick to pick up nettle folding quickly once they start to do it themselves.
Behaviour parsing is useful for imitation learning, but it also allows great apes to have a sort of insight about causality and intentions.
By seeing things happen repeatedly in the same way, you develop a statistical understanding that they always happen that way. This is true both physically (causal) and socially (understanding the intentions of others). In my research on bonobo gestural communication I found that they use intentional gestures, so it is interesting to me that an ability that may have arisen from the need to learn complex food processing can be generalised for social purposes.
There may be two kinds of insight. The great ape insight allows you to make predictions about causality and intentionality based on statistical likelihood, drawing on your past experiences. Without language, that’s where insight stops. Human language allows a second kind of insight, where we can talk about intentions and imagine abstract scenarios that we might not have encountered before.
Richard Byrne’s “heretical thought” is that, as much as we humans like to think that we’re always mentalizing, we actually use the first, great ape insight more than the second. It seems that yes, animals (i.e. great apes) do have “Ah ha!” moments, and that our own human “Ah ha!” moments resemble theirs more than we would like to think.
This is a guest post written by Kirsty Graham. She is a PhD student at the University of St Andrews, where she studies gestural communication in bonobos. Follow her on Twitter at @kirstyegraham. This article is based on Richard Byrne’s new book “Evolving Insight”.