In this paper titled, "Why Concepts Creep to the Left," Jonathan Haidt supplements Nick Haslam's paper titled "Concept Creep," in which concepts such as bullying, trauma and addiction morph over time. And there are newish terms that have become prominent and expansive in recent years, "trigger warnings" and "microaggressions." But these concepts don't merely change. They change to the whims of the political left. And they especially change for current students and young adults rather than those over 40. In his article, Haidt asks why there is a direction to that change. Haidt writes: These terms are part of a new conceptual package that includes all of the older concepts long referred to as “political correctness” but with greatly expanded notions of harm, trauma, mental illness, vulnerability, and harassment. These concepts seem to have expanded in just the way that Haslam (2016) describes -- horizontally, to take in new kinds of cases (such as adding the reading of novels to the list of traumatizing activities) and vertically, to take in ever less extreme versions of older cases (as is made explicit by the prefix “micro” in the word “microaggression”). In this conceptually augmented political correctness, the central idea seems to be that many college students are so fragile that institutions and right-thinking people must all work together to protect vulnerable individuals from exposure to words and ideas that could damage them in a lasting way. If this protection requires banning certain speakers from campus, or punishing student newspapers that publish opinions that upset the dominant campus sensibility, then so be it. What are the reasons for this expansion of these concepts to the left. Haidt explores several possibilities . ..