Hygiene isn’t just cleanliness for its own sake, or for comfort—it’s specifically for maintaining health. But what sets it apart from other health practices is that it’s not targeted, unlike medications or surgeries. When you’re sanitizing the environment, you’re trying to neutralize microbes to lower the risk of infections, but you don’t really know what specific microbes you’re defending against.
The late Daniel Kahneman, of ‘Thinking, Fast and Slow’ fame, promoted the idea that hygiene applies to decision-making as well. As phrased by Clearer Thinking:
There are things you can do (like the mental equivalent of washing your hands) that will help you avoid mistakes, even when you don’t know which mistakes you’ll be avoiding.
The concept itself isn’t particularly novel to anyone passionate about critical thinking and rationality, although the term is a helpful metaphor for the pursuit of ever-better reasoning, which is akin to a constant defense against the unexpected or unidentified traps of fallacies, biases, and errors.
Googling the term, it appears that decision hygiene often takes the shape of checklists. A Farnam Street blog post, for example, recommends checks against self-interested biases, the affect heuristic, groupthink, saliency bias, confirmation bias, availability bias, and so on. Another blog post, from Appeal Finder, adapts Kahneman’s formula into a series of challenges, such as “Have you inadvertently substituted the right question for an easier question?” and “Have you included an ‘outside’ view?” (As I said, I was just googling, and clicking mindlessly on the results, but Appeal Finder is apparently a niche search service for decisions issued by the UK Planning Inspectorate; one could see why they would be interested in better decision-making.)
Decision hygiene, in a way, is basically the exercise of forcing one’s self to go through a rigid process of debiasing. On a more dramatic, perhaps cringe-inducing note, and to badly mix metaphors: decision hygiene wields the sanitizing light of reason to vigorously dispel shadows of ignorance.
One thing that Kahneman and his co-authors on ‘Noise: A Flaw in Human Judgment’ do contribute to decision science is a structured synthesis of these checklists, which they call the mediating assessments protocol. For a description of the protocol’s six steps (and because I haven’t yet read ‘Noise’), I refer the reader to theuncertaintyproject.org.