Rationality is bullshit — Part 1

The term ‘rationality’ and its derivatives lack accuracy, more often than not meaning whatever the person using it wants it to mean. Might nailing down the definition salvage it?

Are you a rational being? Or rather Predictably irrational, as the popular, but now somewhat discredited, behavioural scientist Dan Ariely argued — or indeed Optimally Irrational, as economist Lionel Page proposes? In this and the next article, I will look at how useful the notion of rationality is.

Neoclassical economists have long used homo economicus as their model for the idealized human: someone who is narrowly self-interested, and who seeks to maximize utility through a process of rational decision-making. Even though this description may not have been intended as a normative judgement (maximizing utility is good, is best attempted through rational decision-making, therefore rational decision-making is good), the implication is often that it is superior, and anything else is somehow flawed. Even though we, humans, may not always live up to the ideal of homo economicus, we still ought to strive towards it — otherwise we are being irrational.

That may not sound all that unreasonable (!), but when we scratch the surface, the concept of…