Santos studies comparative cognition in primates including humans, chimps, various monkeys, and (my favorite animal) lemurs! There isn't too much about rationality that we don't share with the rest of the primate family.
What makes humans different in irrationality? Well, actually, a lot of us are indeed similarly stupid to most monkeys -- cognitively speaking, because of biases, heuristics, errors in judgment.
It's amazing that we can even become adult humans at all, says Santos. Her research delves into what causes us to be irrational, our "cognitive dissonance."
Cognitive dissonance, it turns out, is shaped by decisions and preferences that lead to our decision making. And, she presented examples of experiments of how they found in adults and children that preferences change dependent on prior decision making.
For example, when children are forced to choose between two stickers (one showing a fish, another animal), they later express avoidance for choices they previously chose against when no additional information is given (Psychological Science, 2007).
Then, the same experiment was performed on monkeys (with M&Ms, not stickers) and found the same -- they prefer to avoid the one they avoided befofe -- when no new information was presented.
She also went through other experiments, in which it was found that we and monkeys consistently make irrational decisions.
A real-world example of irrationality? Our economic choices are often irrational. If we get a $20 parking ticket our emotional responses are often greater than the opposite response produced if we happened to find a $20 bill on the street.
Santos then brought in some audience participation giving us simple choices in which we'd have to make some kind of risk analysis. If we have a coffee mug for sale, we often have a higher perceived value of it versus if we were buying it.
Basically, the feeling you get from potential loss aversion is often stronger than the feeling you get from potential gain.
In a primate trading method experiment, Santos describes how her team gave monkeys tokens to buy "products" and she shows a video of the monkeys making choices depending on the products given.
Do monkeys have a concept of ownership? She showed that the "endowment effect" does exist in monkeys. If given cereal or fruit (which they treat with equal preference) to trade for the opposite, they will prefer what they were originally given. However, if the monkeys are given the choice of trading their goods for a "good deal" like fruit roll-ups, then they'll capitalize the opportunity.
The capuchins evaluate choices relative to reference points, they exhibit loss aversion, endowment effect, and switch preferences depending on how risk is presented (avoiding loss aversion).
"What we're starting to discover..." Santos says, "a lot of these irrationalities are shared broadly across the primate order suggesting that they originated in a common ancestor."
So, what are the next steps? "We like to think of our species as special," so if we find the kinds of things that show a unique bias, then we can understand more about what makes humans unique.
Also, how does advertising work? They're designing experiments where they show advertisements to the monkeys like an alpha male drinking Coke versus Pepsi, with the thought suggested, "Be alpha male, drink Coke!"
In short, Santos proposes, we can learn a lot about ourselves by researching not just how smart we are, but how "dumb we are" too. After all, we are apt to purposely lose with intent of punishing others, an example of emotional human irrationality.
There may even be cases of uniquely human irrationalities.
Location:Chapel St,New Haven,United States