Storytelling is not always beneficial within a society or community if the stories in question serve primarily -- or even secondarily -- to perpetuate myths that dehumanize other communities or societies. The pernicious effects of such storytelling, say, those that attack ethnic minorities for perceived grievances from generations ago, can be deadly, even leading to genocidal campaigns against those minorities.
On a lighter note, storytelling can be beneficial, and certainly entertaining, when the subject matter is harmless and not intended to belittle or dehumanize others. Such is the case with the stories of Washington Irving. The use of subtitles by authors may have gotten out of control in the modern era. When approaching literature from earlier eras, however, it is a good idea to pay attention to subtitles, as well as to the full titles of works that have been truncated for purposes of brevity among popular usage. For purposes of responding to this particular student question, The Legend of Sleepy Hollow is a case in point. Irving's short story has a subtitle: "Found Among the Papers of the Late Diedrich Knickerbocker." The reason for the interest in this otherwise innocuous appendage to the main title is that it adds greatly to the storytelling tradition that seeks to advance, if only for entertainment purposes, the notion of authenticity that lends good storytelling an important aura. Right from the start, Irving lends his story such an aura, an aura further developed by the brief history of the real-life communities of Tarry Town and Sleepy Hollow in New York State. Into this real-life atmosphere Irving injected his fictional persona of Diedrich Knickerbocker, a recurring figure in his literature. Having thus developed both a realistic setting and a fictional but somewhat plausible persona, Irving then contributes greatly to the development of American storytelling.
Is Irving's story The Legend of Sleepy Hollow beneficial and/or entertaining? Putting aside the subjective nature of art, one can easily conclude that the story is entertaining. In fact, repeated productions of Sleepy Hollow over the years and the current television series adapted from Irving's story attest to the continued public interest in the underlying story of a headless horseman traumatizing a community. We can, therefore, conclude that the story is entertaining. Whether it is beneficial, however, is another matter. Harmless entertainment can in-and-of-itself be beneficial, as temperament can be influenced by well-produced imagery, and many people love good horror stories, especially those with a more gothic bent. Myths have been around since the dawn of recorded time, dating as far back as one thousand years before the reported birth of Jesus. They survive because they are both entertaining and help certain civilizations understand the world around them and the larger universe. If those understandings are grounded in fictional stories, that is not necessarily good. In more technologically and culturally advanced societies, however, the mythology helps provide a more literate culture, which is usually positive.