Decision Theory / Bounded Rationality
Why Your Brain Stopped Calculating and Started Guessing
The part of you that makes decisions isn't a rational calculator — it's an exhausted approximator doing its best with borrowed tools.
The Idea
Classical decision theory imagined the human mind as something like a supercomputer: feed in the options, weigh the probabilities, maximise the outcome. Economists built entire models on this fiction. Then Herbert Simon, a polymath who would eventually win the Nobel Prize in Economics, pointed out the obvious thing everyone had been politely ignoring — actual humans don't work like that, and they never could. Simon called the real phenomenon 'bounded rationality.' The idea is that rationality doesn't fail in us because we're lazy or irrational — it fails because it runs into hard limits. We have finite time, finite cognitive capacity, and access to only a fraction of the information that would theoretically be relevant to any given choice. So instead of optimising, we do something more pragmatic: we satisfice. We search through available options until we find one that is good enough, then we stop. This isn't a bug. It's an elegant adaptation to a world that would paralyse a true optimiser. The problem emerges when we don't notice we're doing it — when we mistake a satisficed decision for a fully considered one, or when the heuristics we're unconsciously running are poorly calibrated for the situation we're actually in. The boundaries of our rationality are invisible to us from the inside, which means we're always, to some degree, deciding without knowing the shape of the decision we're making.
In the World
In the 1950s, Simon and his colleagues studied how executives at large corporations actually made decisions — not how economics textbooks said they should, but how they did. What they found was striking: managers rarely searched exhaustively for the best option. They set an internal threshold — not always consciously — and went with the first option that cleared it. A good enough supplier. A good enough hire. A good enough strategy. Decades later, the psychologist Gerd Gigerenzer took this further by rehabilitating the heuristics Simon had identified. Where many researchers saw mental shortcuts as sources of error, Gigerenzer argued they were often genuinely smart — precisely because they ignored information. His 'Take the Best' heuristic, for instance, showed that in uncertain environments, a decision rule that uses just one good reason often outperforms models that laboriously weigh dozens of variables. The extra information doesn't add clarity; it adds noise. This plays out in medicine, where experienced clinicians sometimes outperform diagnostic algorithms not by processing more data but by knowing which single signal to trust. It plays out in chess, where grandmasters don't calculate every possible move — they pattern-match to a manageable set of promising lines. Bounded rationality, it turns out, isn't the consolation prize for not being a computer. In the right conditions, it's the winning strategy.
Why It Matters
Knowing you are a bounded reasoner changes how you relate to your own decisions — and your own doubt. That nagging feeling that you haven't thought something through enough, that you should research more before committing? Sometimes it's wisdom. But often it's a misunderstanding of how good decisions actually get made. No amount of additional information will get you to certainty; at some point, you are always satisficing. The more useful question becomes: are your thresholds well-set? The internal bar you're unconsciously using to decide when something is 'good enough' — in a relationship, a job, a way of spending your time — was almost certainly formed in a different context than the one you're now in. It may be too low in places where you've learned to accept less than you should. It may be absurdly high in places where perfectionism has dressed itself up as standards. Mindfulness enters here not as a remedy but as a light. Slowing down doesn't give you infinite cognitive capacity — but it can make the shape of your heuristics briefly visible, which is the first step toward questioning them.
A Question to Ponder
Where in your life are you satisficing — and do the thresholds you're using actually reflect what you value now, or what you settled for once and never revisited?
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