Robin Hanson's homo hypocriticus has something missing---- I don't know what to call it, but it's missing.....
False but non-detrimental-signaling (just rolls off the tongue doesn't it?)
Self-evaluation bias, perhaps? If someone believes they are a good person and attributes their actions to an altruistic motive, this may not be accurate, but is consistent with their other delusions (everyone being smarter, more attractive and a better astrophysicist than average.)
Maybe, some people do X because of Y (i.e. are "genuine,") then because other people want to be trusted (Z) they do Y. If the Z'rs don't break faith on other matters, their usurpation of the title X'rs might not be believed, but it may increase trust (which in turn could improve the outcome of interactions, and feeds into the "X fantasy")
Such lies may not increase productivity or societal stability, but they are easier to "maintain" than the truth, perhaps that partially explains the pervasive errors in determining causality.