In Are We Smart Enough to Know How Smart Animals Are? Frans de Waal reports what I think is an enlightening experiment. One argument he makes throughout this book is that Darwin was right when he said that the human mind differs from the minds of other animals only in degree, not in kind. In other words, our humanity is biologically rooted and there is no discontinuity in our evolution; all we can do mentally is prepared for by prior evolutionary progress. De Waal shows how other animals remember, think ahead, conceal to gain advantage, show a sense of fairness, organize socially, delay gratification, make and use tools, and diverse other actions that some have said were exclusively human. His focus on the power of empathy and empathic communication is powerful. What about symbolization, I hear you ask after reading the title of this blog (if not before)? Ah, here is that enlightening experiment.
In a design called ‘reversal pointing’ a chimpanzee (because they are so very bright) is taught to indicate which reward he or she wants by pointing, choosing the larger pile for themselves and leaving the smaller pile for a friend. Then the contingency is changed and the reward they are given is the one not pointed to, i.e., the reverse. Now the chimps can learn to cope with many different contingencies, old, new and changing, but when faced with a small and large pile of candies or fruits, they consistently point to the larger even when the reverse pointing condition is in effect (just like human preschoolers probably before we explain it). Somehow they cannot adjust to point to the smaller pile in order to gain the larger.
But some chimps have been trained to use numbers in making their choice so that they point to 9 or 10 before 1-8 because 9 candies are better than 8, etc. Who knew? And here is the brilliant thing: chimps using numbers, i.e., symbols of at least the iconic sort, cope quite readily with the reversal pointing protocol. They will point to 9 to get more than 8, but if the researcher reverses this, they will point to 8 to get 9. See the difference? Using numbers rather than visual appraisal of quantity allows the chimps to control their mental information, understand the tricky contingency, and adapt their behavior for success by ignoring perceptual information. Therein, it seems to me, lies a glimpse of our evolution into symbolizing creatures. No need to travel on from here, just draw from our biological roots and bask in Gaia’s glow. And thank you, Frans de Waal.