Ecological Rationality

Kahneman vs Gigerenzer

The popular view amongst the self help/pop psych community is that humans are fundamentally irrational. This viewpoint is well backed, mainly by the work of Kahneman and Tversky which I and many others have written about ad nauseum. In his book, Thinking Fast and Slow, Kahneman aimed to disprove that we are rational actors, or “Homo Economicus” as deemed by previous behavioral economists and instead show that we are predictably irrational. The foundation of his entire hypothesis is the idea of system one and system two thinking. System one is automatic, emotional, and intuitive like knowing that 2+2=4 or reading a billboard as you drive by. This is where most of our decision making and cognitive processing takes place as it is more costly and effortful to use system two. System two is logical, effortful, and far slower, this is what takes place when asked a math problem more like 34/2.5 or when we are trying to teach someone else a new task. Because system 2 is more costly, both because it is effortful and because it literally burns more calories, we have developed mental shortcuts. Unfortunately, as Kahneman points out, these short cuts are oftentimes irrational when compared to a purely logical decision making process. One of the most famous examples is the availability heuristic. The availability heuristic describes the cognitive shortcut of estimating probabilities based on how easily examples come to mind. After the tragic events of 9/11 the public viewed flying as more dangerous which led to more people driving more miles. This increase in driving over flying led to ~1,595 “extra” deaths on the roads in the year following the tragedy. The vivid nature of the attack correlated any thought of air travel with danger leading to an increase in perceived probability of danger. Through Kahneman’s and many pop psych/self help personalities view this is irrational as the numbers plainly show that air travel is far more safe.

When we compare the mental shortcuts we use to a purely logical, rational decision making process we are highly irrational creatures and the ideas proposed by those who support the irrationality view are correct. Psychologist Gerd Gigerenzer however proposed an alternative hypothesis. Our heuristics are not irrational but are/were adaptive given the constraints. Khanaman compares rationality to what mathematical equations or formal logic would tell us to, also known as normative standards. Gigerenzer proposes that the ecology, or environment and context determines what is rational or not. Put simply:

Kahneman : deviation from the norm is irrational

Gigerenzer: successful outcome is rational

Gigerenzer’s is famous for coining the phrase fast and frugal when describing our cognitive processes. He argues that they were adaptive mechanisms to make decisions and formulate answers that were good enough for the problem at hand (satisfysing) given the constraints and lack of information in our ancestral environment. For example, the availability heuristic can be seen as adaptive as in our era of evolutionary adaptiveness, how easily something could be called to mind was highly correlated with its probability. When environments are relatively stable and information flows are not skewed, the availability heuristic is actually pretty accurate. His famous breakdown of the 9/11 driving accident statistics mentioned above is one in which he acknowledges the mental error but still believes that the error is rational given the data people had. All else being equal it did seem as though flying was more dangerous so they were acting more rationally. The Kahneman view is nice in riddles and odd contexts like lab rooms and the Linda bankteller question but in the real world, most of our heuristics are actually pretty useful. This is known as ecological rationality, the idea that we are rational actors when the context and constraints in which we are operating within are taken into consideration.

It is not that the heuristics have led us to be fundamentally irrational, that would be quite dire and even Kahneman himself co-wrote an article which states “knowing you have biases is not enough to help you overcome them. You may accept that you have biases, but you cannot eliminate them in yourself.”. Other studies show that we are better at identifying biases in others better than we are at identifying them in ourselves. Instead, the more useful view is to see our biases as adaptive and ask the question “in what ecology is this thought, behavior, or action, rational”. This framework is far more useful as it explains our reasoning for acting or thinking the way we do as something that can be changed, i.e. our ecology, rather than an inevitable defect of the mind.