Some environments are worse than irregular. Robin Hogarth described "wicked" environments, in which professionals are likely to learn the wrong lessons from experience. He borrows from Lewis Thomas the example of a physician in the early twentieth century who often had intuitions about patients who were about to develop typhoid. Unfortunately, he tested his hunch by palpating the patient's tongue, without washing his hands between patients. When patient after patient became ill, the physician developed a sense of clinical infallibility. His predictions were accurate--but not because he was exercising professional intuition!

--Daniel Kahneman in Thinking, Fast and Slow