Cognitive biases are pervasive human instincts. They are essentially shortcuts or heuristics we use all the time to make quick judgments. They crop up whenever we make decisions especially when time is limited and facts are scarce. The heuristics and biases field has burgeoned and flourished and its main exponent is the psychologist Daniel Kahneman. His book Thinking, Fast and Slow is a bestseller, and it was the subject of a recent Practical Neurology Book Club.
The general perception is that biases impair logical reasoning. There is however a lot of debate about whether heuristics and biases are evils to avoid, or virtues to apply carefully and selectively. Several authors have projected the positive aspects of biases, and the most prominent book is perhaps Gary Klein’s Sources of Power: How People Make Decisions.
How do biases and heuristics impact on neurological practice? My first clue to this was in an article in the Annals of Neurology titled How Neurologists Think: A Cognitive Psychology Perspective on Missed Diagnoses. This masterpiece explored the major biases which may lead neurologists astray when they make diagnoses. Using appropriate clinical vignettes the authors exhaustively discussed five classical biases:
A more recent article in the journal Neurology also dwelt on the importance of shortcuts in neurological clinical reasoning. The article, aptly titled Recognising and Reducing Cognitive Bias in Clinical and Forensic Neurology, addresses some other significant biases:
The consensus seems to be that biases are very effective when experts use them in their specific fields. However we need to be aware when we are misapplying them. Neurologists, like all physicians, need to monitor their thinking process carefully to avoid making quick but inaccurate clinical judgments. Fortunately both articles discuss the de-biasing strategies which help to prevent the pitfalls of cognitive biases.
There are many other cognitive biases out there, aiding and laying traps in equal measure. Rolf Dobelli for instance lists 99 biases that may impair our thinking in his excellent The Art of Thinking Clearly. I have reviewed this and other decision-making and patient safety books on other blog:
OK I admit it-I am making a shameful pitch for my other blog…but why not?