Kids like video games; U.S. citizens value individual freedom; people who drop out of high school do not get the best jobs. These broad statements contain stereotypes—standardized or fixed ideas about a group. To some extent, we all think in terms of stereotypes, and sometimes they can be helpful in making a generalization. Stereotyping any individual on the basis of generalizations about a group, however, can lead to inaccurate and even hurtful conclusions.

For example, an instructor who notes a fraternity member’s absence from class on the morning after a big frat party and jokes that he must have a hangover is stereotyping the student on the basis of assumptions about fraternity men. But such stereotyping may be far off the mark with this particular student—and with many other fraternity members. By indulging in it, this instructor may well be alienating some students and proving less effective as a teacher.

Because stereotypes are often based on half-truths, misunderstandings, and hand-me-down prejudices, they can lead to intolerance, bias, and bigotry. But even positive stereotypes—for example, Jewish doctors are the best—or neutral ones—college students like pizza—can hurt, for they inevitably ignore the uniqueness of an individual.

Other kinds of unstated assumptions also destroy common ground by ignoring the differences between others and ourselves. For example, a student in a religion seminar who uses we to refer to Christians and they to refer to members of other religions had better be sure that everyone in the class is Christian, or some people present may feel left out of the discussion.

Sometimes assumptions even lead writers to call special attention to a group affiliation when it is not relevant to the point, as in a woman bus driver or a white basketball player. Decisions about whether to generalize about a group or to describe an individual as a member of a group are often difficult for writers. Think about how your language can build—rather than destroy—common ground.