Herbert Simon noted that people are not omniscient and cannot solve all problems with reason alone, and introduced the principle of bounded rationality:
“The capacity of the human mind for formulating and solving complex problems is very small compared with the size of the problems whose solution is required for objectively rational behavior in the real world or even for a reasonable approximation to such objective rationality” (Simon 1957, p. 198).
What could be the cause of the limitations of the mind? Thinking combines instincts, practices and reason, which are developed to varying degrees by natural and cultural selection. Actions based on instincts and the consistent learning of many generations of people are performed faster and more easily than actions that have emerged relatively recently or require reasoning. Daniel Kahneman calls fast intuitive thinking System 1, and the slow conscious thinking System 2. System 1 is associative, metaphorical, deterministic thinking that comes easily and is automatic, and System 2 is probabilistic statistical thinking that requires a lot of reasoning and reflection. Humans strive to reduce problems to what they supposedly know, to automatic associative and causal correlations. The limitations of reason and our deviations from rationality are explained not by instincts or emotions interfering with reason, but by the mechanism of thinking itself, in which reason is only a later, albeit important, element. This prevents us from recognizing “a puzzling limitation of our mind: our excessive confidence in what we believe we know, and our apparent inability to acknowledge the full extent of our ignorance and the uncertainty of the world we live in” (Kahneman 2011, pp. 13-4).
According to Ken Binmore, rationality is not determined by the ability of humans to foresee the consequences of their actions, but by whether these actions enable humans to reproduce themselves:
“Even when people haven’t thought everything out in advance, it doesn’t follow that they are necessarily behaving irrationally. Game theory has had some notable successes in explaining the behavior of spiders and fish, neither of which can be said to think at all. Such mindless animals end up behaving as though they were rational, because rivals whose genes programmed them to behave irrationally are now extinct. Similarly, companies aren’t always run by great intellects, but the market is often just as ruthless as Nature in eliminating the unfit from the scene” (Binmore 2007, p. 2).