Some people excel at critical thinking; others, not so much. Scientist Carl Sagan and investor Charlie Munger are oft-mentioned exemplars; my friend and colleague Paul Monk is less famous but also impressively sharp. On the other side we have… well, Homer Simpson can stand in for all those it would be rude to name.

But what makes a thinker more highly critical than others? And how can any person lift their game? This can be explored through the notion of habits. Highly critical thinkers have developed many habits which help them think more effectively. With sufficient commitment and patience, and perhaps a little coaching, such habits can be acquired by the rest of us.

This post describes seven major habits of highly critical thinkers. The list is obviously inspired by the hugely successful book about highly effective people. Whatever one might think of that book, if a similar exercise for critical thinking could have even a tiny fraction of its impact, it would be well worth undertaking.

Everybody is familiar with the term “critical thinking,” and has a reasonable working sense of what it is, but there is much disagreement about its proper definition. There’s no need to enter that quagmire here. Suffice to say that critical thinking, for current purposes, is truth-conducive thinking, i.e., thinking that leads to correct or accurate judgements. It is, in a phrase I like to use, the art of being right – or at least, of being more right more often.

But what kind of thinking conduces to truth? What is this subtle art? Back in the early seventeenth century, the philosopher Francis Bacon characterised it this way:

For myself, I found that I was fitted for nothing so well as for the study of Truth; as having a mind nimble and versatile enough to catch the resemblances of things … and at the same time steady enough to fix and distinguish their subtler differences; as being gifted by nature with desire to seek, patience to doubt, fondness to meditate, slowness to assert, readiness to consider, carefulness to dispose and set in order; and as being a man that neither affects what is new nor admires what is old, and that hates every kind of imposture.

Four hundred years later, political scientist Philip Tetlock conducted extensive and rigorous studies of hundreds of experts in the political arena, focusing on their ability to forecast. He found that the experts fell into two main groups:

One group of experts tended to use one analytical tool in many different domains; they preferred keeping their analysis simple and elegant by minimizing “distractions.” These experts zeroed in on only essential information, and they were unusually confident—they were far more likely to say something is “certain” or “impossible.” In explaining their forecasts, they often built up a lot of intellectual momentum in favor of their preferred conclusions. For instance, they were more likely to say “moreover” than “however.”

The other lot used a wide assortment of analytical tools, sought out information from diverse sources, were comfortable with complexity and uncertainty, and were much less sure of themselves—they tended to talk in terms of possibilities and probabilities and were often happy to say “maybe.” In explaining their forecasts, they frequently shifted intellectual gears, sprinkling their speech with transition markers such as “although,” “but,” and “however.”

The second group, the “foxes,” were better forecasters than the first, the “hedgehogs.” Foxy thinking, it seems, is more truth-conducive than hedgehoggery.

Two points jump out from these quotes. First, the two accounts have much in common, underneath the differences in style. The essence of critical thinking is largely stable across the centuries.

Second, they are both describing what good thinkers tend to do. Theorists of critical thinking have various ways of thinking about these tendencies; some talk of dispositions, others of virtues. Here I take what may be a novel approach and consider them as acquirable habits.

A habit is just a propensity to take actions of a certain kind in a relatively automatic or reflexive manner. And as we all know, and as elaborated in the recent book by Charles Duhigg, The Power of Habit, good habits can be cultivated, and bad habits overcome. So the goal here is to list:

  • propensities to do things of certain kinds more or less automatically under appropriate circumstances; which propensities are
  • possessed by highly critical thinkers much more often than by ordinary folk, and which
  • help them to make more correct or accurate judgements, and
  • could be picked up, or further developed, by any ordinary person with a reasonable amount of effort; with the result that
  • they would themselves become more critical.

The habits described below are the kinds of things highly critical thinkers really do do. They are not merely prescriptions or guidelines which would help anyone to be more critical if anyone were disciplined or virtuous enough to follow them.

To illustrate: Blogger Shane Parrish reports that a hedge fund manager and author, Michael Maubousson, asked the Nobel-winning psychologist Daniel Kahneman what a person should do to improve their thinking. “Kahneman replied, almost without hesitation, that you should go down to the local drugstore and buy a very cheap notebook and start keeping track of your decisions.”

Now, it is plausible that keeping track of your decisions in a notebook would improve your thinking. However, it is not a habit of highly critical thinkers, at least in my experience. I don’t recall ever observing a highly critical thinker doing it, or hearing one say they do it. I don’t even do it myself, even after hearing the great Laureate’s advice (and apparently Maubousson doesn’t either).

And so to the habits themselves.

1. Judge judiciously

One of the most salient thinking traps is, in the common phrase, jumping to conclusions. Highly critical thinkers have cultivated four main habits which help them avoid this.

First, they tend to delay forming a judgement until the issue, and the considerations relevant to it, have been adequately explored, and also until any hot emotions have settled (Bacon’s “slowness to assert”).

Second, they tend to abstain altogether from making any judgement, where there are insufficient grounds to decide one way or another. They feel comfortable saying, or thinking, “I don’t know.”

Third, when they do make a judgement, they will treat it as a matter of degree, or assign a level of confidence to it, avoiding treating any non-trivial issue as totally certain.

And fourth, they treat their judgements as provisional, i.e., made on the basis of the evidence and arguments available at the time, and open to revision if and when new considerations arise.

2. Question the questionable

Much more often than ordinary folk, highly critical thinkers question or challenge what is generally accepted or assumed. Sometimes they question the “known knowns” – the claims or positions which constitute widely-appreciated truths. Other times, they target the implicit, the invisible, the unwittingly assumed.

Highly critical thinkers do not of course question everything. They are not “radical skeptics” doubting all propositions (as if this was even possible anywhere other than in philosophical speculation). Rather, they tend to be selective or strategic in their questioning, targeting claims or positions that are worth challenging, whether in some practical or intellectual sense. They are skilled in identifying or “sniffing out” the “questionable,” i.e. claims which are potentially vulnerable, and whose rejection may have important or useful implications.

3. Chase challenges

We all know that feeling of instant irritation or indignation when somebody dares to suggest we might be wrong about something. Highly critical thinkers have cultivated various habits counteracting this reaction – habits which actually lead to them being challenged more often, and benefiting more from those challenges.

For example, while we mostly seek and enjoy the company of those who share our views, highly critical thinkers make an effort to engage those of a contrary opinion, tactfully eliciting their objections. And when fielding such challenges, highly critical thinkers resist the instinct to ignore, reject or rebut. They will be found doing such seemingly perverse things as rephrasing the objections to be sure of understanding them, or even to render them even more powerful. Charlie Munger is quoted as saying “I never allow myself to have an opinion on anything that I don’t know the other side’s argument better than they do.”

Another habit of highly critical thinkers is reading widely, and especially reading from sources likely to present good quality contrary views and arguments. Finding themselves drawn to a position (e.g., that William Shakespeare of Stratford was unlikely to have been the author of the works attributed to him) highly critical thinkers seek out the best presentations of the orthodox position. In short, they strive to test or “prove” their views, rather than support or defend them.

4. Ascertain alternatives

Highly critical thinkers are always mindful that what they see before them may not be all there is. They habitually ask questions like: what other options are there? What have we missed? As opposed to/compared with what? They want to see the full range of relevant alternatives before passing judgement.

For example, when considering a difficult decision, they put extra effort into searching for – or creating – courses of action outside the standard, provided or obvious ranges. When trying to explain why something happened, they will allocated more time than most people do to expanding the range of hypotheses under consideration. In a negotiation, they seek to develop new, mutually acceptable solutions rather than “horse-trading” on existing positions.

5. Make use of methods

When considering a course of action, a critical thinker of my acquaintance, who happened to be successful banker and company director, said she always asked herself two simple questions: (1) what’s the worst thing that could happen here? and (2) what’s the best thing that could happen? The first question prompts us to search for potential drawbacks a bit more thoroughly than we might otherwise have done. The routine amounts to a rudimentary (or “fast and frugal”) risk analysis.

This example illustrates how highly critical thinkers habitually deploy suitable methods to structure their thinking and improve the conclusions. Another example: in psychology department colloquiua I used to attend, participants, after hearing a colleague present their work, would reflexively use a method I call scenario testing. This involves diligently and creatively searching for scenarios in which their colleague’s conclusions are false, even though their premises (data) are true. To the extent that plausible scenarios of this kind can be identified, the inferences from the premises to the conclusions are suspect.

There are literally scores of methods one might use. Some, like the rudimentary risk analysis mentioned above, are simple and informal, and can be quickly learned and exploited by almost anyone. Others are elaborate, technical and may require specialist training (e.g., rigorous argument mapping, or full quantitative risk analysis). Generally, the more sophisticated the method, the less widely it is used, even by the most highly critical thinkers. Every such thinker has built up their own repertoire of methods. What’s most important is not so much their particular selection, but the fact that they habitually deploy a wider range of methods, more often, than ordinary folk.

6. Take various viewpoints

Highly critical thinkers well understand that their view of a situation is unique, partial and biased, no matter how clear, compelling and objective it seems. They understand that there will always be other perspectives, which may reveal important aspects of the situation.

Of course, most people appreciate these points to some degree. The difference is that highly critical thinkers are especially keen to profit from a more complete understanding, and so have cultivated various habits of actually occupying, as best they can, those other viewpoints, so as to see for themselves what additional insights can be gained.

One such habit is trying to “stand in the shoes” of a person with whom we may have some conflict, or are inclined to criticise. Another is to adopt the persona of a person, perhaps a hypothetical person, who strongly disagrees with your views, and to argue against yourself as strongly as they would. A third (relatively rare) is to take the perspective of your future self, having found out that your current position turned out to be wholly, and perhaps disastrously, wrong. What do you see, from the future, that you are missing now?

7. Sideline the self

People tend to be emotionally attached to views. Core beliefs, such as provided by religions or ideologies, help provide identity, and the comforts of clarity and certainty. Sometimes pride binds us to positions; having publicly avowed and defended them previously, it would be humiliating to concede we were wrong. Highly critical thinkers have habits which help to sever these emotional bonds between self and beliefs, allowing the thinker to discard or modify beliefs as indifferently as a used car dealer will trade vehicles. Highly critical thinkers have in other words learned how to sideline the self, removing it from the field of epistemic play.

One habit is to avoid verbally identifying oneself with positions by using distancing locutions. Instead of saying things like “Its obvious to me that…” they will say things like “one plausible position is that”. A similar technique is to give positions names. Instead of boldly asserting that Shakespeare must have written the works, publicly committing yourself to this view, say “According to the Stratfordian view…”.

To be continued…

This post is already much longer than originally intended, but still leaves much unsaid. A few quick final points:

  • The current list can’t claim to be definitive. Others may well come up with different lists.
  • It is also a work in progress. I hope to elaborate each of the major habits in separate posts.
  • Clearly much more could be said about the notion of a habit, and the somewhat paradoxical character of critical thinking habits, which generally involve automatically (“without thinking about it”) engaging in thinking activities.
  • This list is not based on rigorous empirical research, though in places it is informed by such research. There is much scope for scientific clarification here. Tetlock’s studies provide an impressive model.

Comments are most welcome.