[T]he psychological roots of progressophobia run deeper.
The deepest is a bias that has been summarized in the slogan “Bad is stronger than good.” The idea can be captured in a set of thought experiments suggested by Tversky. How much better can you imagine yourself feeling than you are feeling right now? How much worse can you imagine yourself feeling? In answering the first hypothetical, most of us can imagine a bit more of a spring in our step or a twinkle in our eye, but the answer to the second one is: it’s bottomless. This asymmetry in mood can be explained by an asymmetry in life (a corollary of the Law of Entropy). How many things could happen to you today that would leave you much better off? How many things could happen that would leave you much worse off? Once again, to answer the first question, we can all come up with the odd windfall or stroke of good luck, but the answer to the second one is: it’s endless. But we needn’t rely on our imaginations. The psychological literature confirms that people dread losses more than they look forward to gains, that they dwell on setbacks more than they savor good fortune, and that they are more stung by criticism than they are heartened by praise. (As a psycholinguist I am compelled to add that the English language has far more words for negative emotions than for positive ones.)
Steven Pinker, Enlightenment Now: The Case for Reason, Science, Humanism, and Progress, New York, 2018, ch. 4