Sandra, I don’t think you need to appeal to Kahnemann’s theory or any fancy psychological terminology here. The problem you’re addressing is straightforward matter for rationality. Everyone has their own individual understanding (Kahnemann re-labels understanding as the ‘ability to make rapid inferences’) based on their experiences, past and reason. That’s human nature and there’s nothing wrong with it. And so it takes good arguments and quality evidence to change one’s understanding. That being said (and that’s a traditional position) I’ve never seen someone change their understanding just based on the “weight of new data”: anyone can derive as much as data on anything they want. I wouldn’t expect anyone to change their views due to data; data is in and of itself meaningless until interpreted. Data needs to be formulated into an argument that appeals to understanding before it means anything. Think of the most obvious case of the “data-weighing” fallacy: clinicians continue to produce positive clinical data for psychiatric drugs even though researchers long ago showed there’s no basis for this. Where’s this positive data coming from then? Clinicians are simply cherry-picking outcomes, excluding AEs & non-responders and ignoring underlying drug mechanisms to produce supportive data. They’re doing a great job of supplying an overwhelming “weight of new data”. I’m sure that they will continue doing this and can do it ad infinitum, even though a rational interpretation of their data immediately shows it to be junk. So we’re left with the good old fashioned human dilemma: how to use our own reason to improve our understanding? From what I see and hear in the medical profession, it seems like physicians constantly struggle with this. You’re always seemingly at at a rational deficit and I think it’s because you’re trained from the outset to use textbook concepts taken on authority. If you take a class in critical thinking, the first thing you learn is that an ‘appeal to authority’ is a glaring logical fallacy and invalid in argument. Unfortunately this uncritical approach in medicine has meant that medical doctrines, disproven by research, can persist for decades, even centuries, and cause tremendous harm, without physicians changing their practices. So, the solution to the problem you raise is simple: use your reason, prove your case and win the argument. Otherwise you’ll be following the “data” into your grave, probably doing great harm and changing no one’s mind.