Plato and Cognitive Bias

One of the ways in which we hide how similar our ancestors are to ourselves, Bertrand Russel noted, is by inventing technical terms for things we knew all along.

[T]he richest precedent for behavioural economics is in the works of ancient Greek philosophers. Almost 2,500 years before the current vogue for behavioural economics, Plato was identifying and seeking to understand the predictable irrationalities of the human mind. He did not verify them with the techniques of modern experimental psychology, but many of his insights are remarkably similar to the descriptions of the cognitive biases found by Kahneman and Tversky. Seminal papers in behavioural economics are highly cited everywhere from business and medical schools to the social sciences and the corporate world. But the earlier explorations of the same phenomenon by Greek philosophy are rarely appreciated. Noticing this continuity is both an interesting point of intellectual history and a potentially useful resource: Plato not only identified various specific weaknesses in human cognition, he also offered powerful proposals for how to overcome these biases and improve our reasoning and behaviour.

Many of Plato’s dialogues dramatise the habits and processes that lead humans to false conclusions. He depicts people believing what they want or what they are predisposed to believe (confirmation bias); asserting whatever comes most readily to mind (availability bias); reversing their opinions about identical propositions based on the language in which the propositions are presented (framing); refusing to relinquish current opinions simply because these happen to be the opinions they currently possess (a cognitive version of loss aversion); making false inferences based on the size and representativeness of a sample of a broader population (representativeness heuristic); and judging new information based on salient current information (a version of anchoring). And this is only a partial inventory of the mental errors that he catalogues and dramatises.

Plato was also very good at math, a point that many contemporary readers miss. The Greeks didn't have algebra, but they did have a highly-advanced approach to geometry that allowed them to solve many complex mathematical problems. Thus, while you might not expect Plato to provide a criticism of contemporary statistical mathematics (since he did not have access to such systems), in fact he's aware of a number of the problems such systems will encounter because he has thought a great deal about the real nature of mathematical objects like numbers and shapes.

It may be hard for contemporary thinkers who are schooled in our advanced forms of mathematics to think there is much to be gained by learning the ancient forms as well. Yet a new way of thinking about the same problems offers unexpected benefits. The philosophical investigation into the nature of mathematicals offers additional benefits. What we often learn is how difficult it is to be sure of what we think we know. Thus:

Intellectual humility and overconfidence can stem from purely cognitive processes, but they are also correctly understood as moral achievements or failings. Someone who always thinks that he is right about everything... is making a moral as well as a mental mistake. Similarly, the cultivation of intellectual humility is, in part, the cultivation of an ethical virtue.