Sherwood Anderson's Winesburg, Ohio is a very interesting, albeit somewhat confusing book.  Even the concept on "the grotesque," which acts as a motif throughout the book, is as difficult to fully visualize as its definition suggests.  In the introductory preface, entitled "The Book of the Grotesque," Anderson presents the following information:

That in the beginning when the world was young there were a great many thoughts but no such thing as a truth. Man made the truths himself and each truth was a composite of a great many vague thoughts. All about in the world were the truths and they were all beautiful.
. . . There was the truth of virginity and the truth of passion, the truth of wealth and of poverty, of thrift and of profligacy, of carelessness and abandon. Hundreds and hundreds were the truths and they were all beautiful.
And then the people came along. Each as he appeared snatched up one of the truths and some who were quite strong snatched up a dozen of them.
It was the truths that made the people grotesques . . . the moment one of the people took one of the truths to himself, called it his truth, and tried to live his life by it, he became a grotesque and the truth he embraced became a falsehood.

To clarify, there is no such thing as an absolute truth.  Rather, the "truths" of the world were created by mankind.  This presents a Deconstructionist approach to the concept of truth.  To a Deconstructionist, the word "truth" is arbitrary.  Like all language, there is no inherent quality that makes truth "truth."  Rather, at some point in human history, someone decided that the word "truth" would be used to represent something factual, something that has "the quality or state of being true," and that was only after all of the other words in the definition has also been given an arbitrary meaning.  Similarly, the various ideas that are contained within the idea of "truth" are also arbitrary, as one person's "truth" may not be another person's "truth."  This is where Anderson's idea of the grotesque comes into play. 

As Anderson states, "the moment one of the people took one of the truths to himself, called it his truth, and tried to live his life by it, he became a grotesque and the truth he embraced became a falsehood."  Consider one of the various "truths" that Anderson himself presents in this section, the truth of poverty.  What is the "truth" of poverty?  Some may say the truth of it is that poor people are lazy, some may say it's that poor people work really hard at jobs that don't pay them fairly.  Some may say that poor people are miserable, while others may say that poor people have a better sense of what is truly important in life.  All of these (and more) are potential "truths," but none of them are the absolute truth of poverty.  However, if someone takes up one of these truths, perhaps the idea that poor people are lazy, calls it his truth, and begins to live his life by it, it makes him become a grotesque.  Therefore if someone were to believe that the one "be all, end all" of poverty is that poor people are lazy, it would twist their worldview, making them perceive the world inaccurately, and in turn it would twist their entire existence into a grotesque.

The grotesques that Anderson presents in the individual chapters are all, in some ways, twisted by some aspect of their worldview.  For example: Wing Biddlebaum's grotesque does manifest itself via his nervous hands, but the grotesque itself consists of his inner belief that his hands do something bad, although he doesn't know what that is.  As a young teacher, he was chased out of a small town upon suspicion of pedophilia, but he never did anything to any children.  Instead, a young child became infatuated with him and begin to say that he did things.  The townsfolk grew angry and Wing, then living under his real name Adolph Myers, was beaten, nearly hanged, and chased out of town.  He has no idea why; he only knows it is connected to his hands because one man named Henry Bradford, while beating Adolph in the schoolyard, kept saying ""I'll teach you to put your hands on my boy, you beast."  Adolph fled the town, took on a new moniker as a result of his nervous, constantly moving hands, and continues to live in constant fear that he will be hunted down and killed because of something that his hands do.  He even sleeps on a folding cot near his front door rather than in a proper bedroom, seemingly because he doesn't know when he might have to flee again. 

Similarly Elizabeth Willard, mother of the main character George Willard, suffers from many things, one being a grotesque connected to the idea of success.  She loathes her husband, Tom, who "was ambitious for his son. He had always thought of himself as a successful man, although nothing he had ever done had turned out successfully."  Tom's own view of himself and his accomplishments is skewed, and his own grotesque regarding success has created in Elizabeth a grotesque as well.  Elizabeth is very protective of George, and wants him to amount to something.  However, her attempts to pray on his behalf end up being convoluted and confusing:

"If I am dead and see him becoming a meaningless drab figure like myself, I will come back," she declared. "I ask God now to give me that privilege. I demand it. I will pay for it. God may beat me with his fists. I will take any blow that may befall if but this my boy be allowed to express something for us both." Pausing uncertainly, the woman stared about the boy's room. "And do not let him become smart and successful either," she added vaguely.

Here Elizabeth wants George to be something for both of them, but at the same time she doesn't want George to be successful, because her view of success has been shaped by her husband's view of his own success.  She understands that she is a failure, but she also believes that Tom, as a success, is something even worse than a failure.  Because of this her wish for her son is a contradiction. 

The grotesques end up controlling the lives of those who suffer from them.  Wing fears the approach of a lynch mob at all times, and grows horrified anytime his hands make contact with another person.  Elizabeth's skewed view is based on that of her husband, and makes her life such that she sees even a simple conversation between her husband and her son as a threat to her son's safety. Even George, the main character, nearly succumbs to his own, initial grotesque view of women.  However, unlike most of the characters in the town, he manages to escape it, leaving Winesburg and its suffering, grotesque citizenry behind.

A grotesque in literature in its broadest sense is a character who in some way is outside the norm, possessed of some sort of aberration. There are many ways to express the grotesque in literature, and in his introduction to the stories in Winesburg, Ohio, Anderson defines a grotesque as a person who tries to live by a single truth that eventually proves distorted. 

In the story "Queer," Anderson creates Elmer Cowley, a character with whom readers can empathize with because of his outsider status. A rustic who has moved to town from a farm, Elmer is poorly dressed, and since his father is unsuccessful as a shopkeeper, the whole family is seen as a failure as both members of the merchant class and their social milieu. 

In "The Teacher," Kate Swift is a grotesque. She is misunderstood by the people in town and ultimately rejected by the men with whom she tries to make a romantic connection. This is true of her behavior with George Willard when she makes a pass at him and then flees.