Sunday, January 13, 2008

The evolution of thought


Perhaps you remember this post by Cheryl recounting an experiment conducted with capuchin monkeys. Researchers taught the monkeys to use tokens as money and then, through a series of changing conditions observed the exchange of tokens for food.

As interestingly humourous as the experiment turned out to be (as the monkeys became more sophisticated in the use of money, some engaged in theft and one became a prostitute) the results have been used in other studies, not about monkeys, but about how the thought processes of humans and non-human primates share certain similarities.

Take this study. Evolution accounts for a lot of our strange ideas about finances.
Here's a related thought experiment. Would you rather be A or B? A is waiting in line at a movie theater. When he gets to the ticket window, he is told that as he is the 100,000th customer of the theater, he has just won $100. B is waiting in line at a different theater. The man in front of him wins $1,000 for being the 1-millionth customer of the theater. Mr. B wins $150. Amazingly, most people said that they would prefer to be A. In other words, they would rather forgo $50 in order to alleviate the feeling of regret that comes with not winning the thousand bucks. Essentially, they were willing to pay $50 for regret therapy.

Regret falls under a psychological effect known as loss aversion. Research shows that before we risk an investment, we need to feel assured that the potential gain is twice what the possible loss might be because a loss feels twice as bad as a gain feels good. That's weird and irrational, but it's the way it is.
And loss aversion, as irrational as it can be when the outcome is as described above, may be something hardwired into our brains. Remember those capuchin monkeys?
... the monkeys were given additional tokens to trade for food, only to discover that the price of one of the food items had doubled. According to the law of supply and demand, the monkeys should now purchase more of the relatively cheap food and less of the relatively expensive food, and that is precisely what they did. So far, so rational. But in another trial in which the experimental conditions were manipulated in such a way that the monkeys had a choice of a 50% chance of a bonus or a 50% chance of a loss, the monkeys were twice as averse to the loss as they were motivated by the gain. Remarkable! Monkeys show the same sensitivity to changes in supply and demand and prices as people do, as well as displaying one of the most powerful effects in all of human behavior: loss aversion. It is extremely unlikely that this common trait would have evolved independently and in parallel between multiple primate species at different times and different places around the world. Instead, there is an early evolutionary origin for such preferences and biases, and these traits evolved in a common ancestor to monkeys, apes and humans and was then passed down through the generations.
That would mean that our thought processes and loss aversion in humans and non-human primates dates back 10 million years.

There's more. Duke University researcher Jessica Cantlon did a different experiment involving mathematical functions.
An experiment testing the arithmetic skills of monkeys and college students revealed that when solving equations without the use of language, student performances were similar to that of the monkeys. [...]

The purpose of this type of research is to understand the evolutionary origins of thought, she said.

“This particular study was designed to compare basic mathematical abilities between humans and non-human primates to determine whether they share an underlying thought process for solving addition problems,” she said.

According to Reuters, the study had 14 Duke students square off against two female macaque monkeys, Boxer and Feinstein.

The experiment required participants to add two sets of dots and choose a stimulus from two options that indicated the arithmetic sum of the two sets.

This study revealed that rather than counting or using language to solve the problems, college students performed this task using a “similar kind of fuzzy arithmetic” the monkeys did, said Cantlon.

“College students non-verbally estimated the arithmetic outcomes of the problems,” said Cantlon.

When performing the task nonverbally, both monkeys and humans typically answered within one second.

Essentially each group was looking at two sets of dots and was provided with possible options of the sum of those dots. Rather than simply count them up, both the humans and the monkeys used the same process to arrive at the correct answer - estimation.

Cantlon said this finding suggests that even complex abilities such as mathematics might appear to have an evolutionary origin.
Again, that would put the origins of thought back about 10 million years to a common ancestor. (I hear heads exploding).

As for the study conducted, both groups of participants were paid for their time. Students received $10, and the monkeys were rewarded with Kool-Aid, according to Reuters.
Too bad Cantlon didn't use the capuchin monkeys. They would have taken the ten bucks, bought some Kool-Aid and had money left over for Jell-O and grapes.

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