Consider the following.
I'm a physician at the end of more than a decade of training. I've dissected cadavers in anatomy lab. I've pored over tomes on the physiology of disease. I've treated thousands of patients with ailments as varied as hemorrhoidsand cancer.
And yet the way I care for patients often has less to do with the medical science I've spent my career absorbing than with habits, environmental cues and other subtle nudges that I think little about.
I'll sometimes prescribe a particular brand of medication not because it has proved to be better, but because it happens to be the default option in my hospital's electronic ordering system. I'm more likely to wash my hands — an activity so essential for safe medical care that it's arguably malpractice not to do so — if a poster outside your room prompts me to think of your health instead of mine. I'll more readily change my practice if I'm shown data that my colleagues do something differently than if I'm shown data that a treatment does or doesn't work.
These confessions can be explained by the field of behavioral economics, which holds that human decision-making departs frequently, significantly and predictably from what would be expected if we acted in purely "rational" ways. People don't always make decisions — even hugely important ones about physical or financial well-being — based on careful calculations of risks and benefits. Rather, our behavior is powerfully influenced by our emotions, identity and environment, as well as by how options are presented to us.