Saturday, 28 February 2015

Apes are affected by framing too!

Classes start next week, and the first week of ECON110 covers (among other things) rationality and quasi-rationality (how human decision-makers deviate from pure rationality). One of the effects that leads to deviations from pure rationality is framing. That is, the way that different options are framed (or presented to us) can affect how we evaluate equivalent choices.

The classic example of framing is an experiment that was run in the early 1980s by Nobel prize winner Daniel Kahneman and Amos Tversky (who almost certainly would have shared the Nobel prize had he not died six years before Kahneman's success). I won't explain the experiment in detail (you can read an explanation of it here or here), but essentially the experiment demonstrates that people are more willing to choose the 'safe' (low risk) option when the options are framed positively, and more willing to choose the riskier option when the options are framed negatively. I run this experiment in my ECON110 class every year, with similar results every time.

So essentially, the particular phrasing that we use to describe a problem can affect the choices we make. Now, new research has demonstrated that chimpanzees and bonobos are also affected by framing. From Duke Today:
A Duke University study has found that positive and negative framing make a big difference for chimpanzees and bonobos too.
In experiments conducted at Tchimpounga Chimpanzee Sanctuary in the Republic of Congo and Lola ya Bonobo Sanctuary in the Democratic Republic of Congo, researchers presented 23 chimpanzees and 17 bonobos with a choice between two snacks -- a handful of nuts and some fruit.
In one series of trials, the researchers framed the fruit option positively -- by offering one piece of fruit, with a 50 percent chance of a surprise bonus piece.
In another series of trials, the researchers framed the fruit option negatively. This time they offered two pieces of fruit rather than one, but if the apes chose the fruit, half the time they were shortchanged and received only one piece instead.
Chimps and bonobos were more likely to choose the fruit over the nuts when they were offered a smaller amount of fruit but sometimes got more, versus when they were initially offered more but sometimes got less -- despite receiving equal average payoffs in both scenarios.
So, it turns out that humans aren't so special after all, and our susceptibility to framing might be hardwired into us. Interestingly, only male apes were significantly affected by framing - maybe that means that female apes are more rational than males? You can read the research paper by Christopher Krupenye (Duke), Alexandra G. Rosati (Yale), and Brian Hare (Duke) here.

[HT: Marginal Revolution]