Ah, crap, now I have to change another lecture slide… No, this is cool. From Science Daily, The Symbolic Monkey? Animals Can Comprehend And Use Symbols, Study Of Tufted Capuchins Suggests discusses research that appeared in PLoS ONE. Some theorists refer to humans as ‘the symbolic species,’ but like so many distinctions that used to seem so clearly differentiating of ‘human nature,’ we find that the distinction is more of degree than kind. For example, studies of chimpanzees and gorillas taught manual or token languages have shown that great apes are capable of using symbols to communicate; whether or not monkeys could was less clear.
In this experiment, the researchers used the equivalent of ‘food standard’ money with monkeys to see how they understood the value of tokens which were equated to different types of food. The Science Daily article explained:
In the experiment, five capuchins engaged in “economic choice” behavior. Each monkey chose between three different foods (conventionally referred to A, B and C), offered in variable amounts. Choices were made in two different contexts. In the “real” context, monkeys chose between the actual foods. In the “symbolic” context, monkeys chose between “tokens” (intrinsically valueless objects such as poker chips) that represented the actual foods. After choosing one of the two token options, monkeys could exchange their token with the corresponding food.
Turns out that the monkeys’ choices were ‘transitive,’ that is, they demonstrated the same preferences whether they were transacting in real food or in intrinsically meaningless tokens that represented the food. It turned out that tufted capuchins preferred Cheerios to parmesan cheese (dumb bastards); however, when transacting in tokens, the rate of exchange between foods became more pronounced. They held out for more parmesan cheese for their Cheerios when using tokens; in actual food, the exchange rate was one Cheerio for two pieces of cheese, but this inflated to one Cheerio for four pieces of cheese (for example) in tokens.
