Everything Is Obvious_ _Once You Know the Answer - Duncan J. Watts [60]
WHOEVER TELLS THE BEST STORY WINS
Historical explanations, in other words, are neither causal explanations nor even really descriptions—at least not in the sense that we imagine them to be. Rather, they are stories. As the historian John Lewis Gaddis points out, they are stories that are constrained by certain historical facts and other observable evidence.12 Nevertheless, like a good story, historical explanations concentrate on what’s interesting, downplaying multiple causes and omitting all the things that might have happened but didn’t. As with a good story, they enhance drama by focusing the action around a few events and actors, thereby imbuing them with special significance or meaning. And like good stories, good historical explanations are also coherent, which means they tend to emphasize simple, linear determinism over complexity, randomness, and ambiguity. Most of all, they have a beginning, a middle, and an end, at which point everything—including the characters identified, the order in which the events are presented, and the manner in which both characters and events are described—all has to make sense.
So powerful is the appeal of a good story that even when we are trying to evaluate an explanation scientifically—that is, on the basis of how well it accounts for the data—we can’t help judging it in terms of its narrative attributes. In a range of experiments, for example, psychologists have found that simpler explanations are judged more likely to be true than complex explanations, not because simpler explanations actually explain more, but rather just because they are simpler. In one study, for example, when faced with a choice of explanations for a fictitious set of medical symptoms, a majority of respondents chose an explanation involving only one disease over an alternative explanation involving two diseases, even when the combination of the two diseases was statistically twice as likely as the single-disease explanation.13 Somewhat paradoxically, explanations are also judged to be more likely to be true when they have informative details added, even when the extra details are irrelevant or actually make the explanation less likely. In one famous experiment, for example, students shown descriptions of two fictitious individuals, “Bill” and “Linda” consistently preferred more detailed backstories—that Bill was both an accountant and a jazz player rather than simply a jazz player, or that Linda was a feminist bank teller rather than just a bank teller—even though the less detailed descriptions were logically more likely.14 In addition to their content, moreover, explanations that are skillfully delivered are judged more plausible than poorly delivered ones, even when the explanations themselves are identical. And explanations that are intuitively plausible are judged more likely than those that are counterintuitive—even though, as we know from all those Agatha Christie novels, the most plausible explanation can be badly wrong. Finally, people are observed to be more confident about their judgments when they have an explanation at hand, even when they have no idea how likely the explanation is to be correct.15
It’s true, of course, that scientific explanations often start out as stories as well, and so have some of the same attributes.16 The key difference between science and storytelling, however, is that in science we perform experiments that explicitly test our “stories.” And when they don’t work, we modify them until they do. Even in branches of science like astronomy, where true experiments are impossible, we do something analogous—building theories based on past observations and testing them on future ones. Because history is only run once, however, our inability to do experiments effectively excludes precisely the kind