I would be remiss as a researcher if I neglected to mention the opposition to Kahneman's heuristics and biases approach to human rationality. As impressive as his work as been, it is not universally accepted in the scientific community. The fundamental question is whether or not we are defining "normal" thinking in the appropriate way, known as the normative model. When Kahneman claims that the subjects in his studies made the "wrong" choice, is it that his standards are artificial, or is he truly exposing flaws in human rationality? A bigger question may be, is there an accurate and purely objective source of rationality? Aristotle defined man as the "rational animal." Animals have the potential to be either rational or arational – devoid of any rational thought. However, humans have the distinction of being the only animals that can behave irrationally. That is, we can make decisions that violate what may be in our best interest. We know that In-n-Out burger is going to clog our arteries, but darn it's tasty! However, simultaneously, rationality is subjective. What may be rational to one person or in one situation may not be to another. If In-n-Out is the only food for 100 miles, and you are starving, it is a rational choice.
As I've written about before, Kahneman and his late colleague Amos Tversky spent decades researching irrationality. In brief, Kahneman's Nobel Prize was given for showing a flaw in economic theories that assumed humans behaved rationality. However, as Keith Stanovich writes, "researchers have found it much easier to measure whether a particular rational structure is being violated...rather than whether their thinking is as good as it can be." He continues to giving the analogy that doctors can easily spot when someone is in ill health easier than when they are in perfect health. As such, "failure to display a cognitive bias becomes a measure of rational thought."
The people in this camp have been termed the Meliorists and take the position that human reasoning could stand to be improved through human effort. They believe that humans are not behaving optimally and ought to improve to coincide with their standards of ideal rationality. However, these standards are often hard to firmly establish.
Conversely, there is a competing camp that believes the results from studies like Kahneman's heuristics and biases studies do not describe irrationality. Rather, they describe the optimal evolutionary adaptation to perceived inputs as the gold standard of rationality. They argue that the subject's interpretation of the task is often different than what the researcher assumes it is. As such, the “cognitive biases” that are demonstrated are not biases at all, but rather problems with the experiment that entrap participants. This group is called the Panglossians.
A tangible consequence of this is highlighted in an article from The Economist I posted a while ago that poses the question of whether advertisers do a service for people by sharing products that they didn't know they wanted, or if advertisers take advantage of people who already know what they want. The Economist argued the latter position.
Moreover there is a philosophical question of whether humans should improve their rational thinking skills or not. We live in a society that champions those with higher rational thinking skills (a proxy measure being IQ tests, though these admittedly are not necessarily the best measures). Nevertheless, the average American will live their life without ever having any sort of training to improve their rational thinking and avoid cognitive biases, and society has made it as far as we have.
Interestingly, since about the 1930s, IQ test scores in developed countries have slowly but steadily increased, dubbed the Flynn Effect. Are humans getting smarter or are we just getting better at taking tests? My gut says that we are getting better at teaching and cultivating rational thinking in students, aligning with the Meliorist view.
I can't offer any conclusion to this debate, but the question of what is optimal rationality is an interesting one to ponder. Few things in this world are black and white - could we ever truly find an objective rational truth? That's a subject of a future post I'm sure.