At a psychology conference in England years ago, a woman said to me: "I'll knock you up in the morning." I was taken aback by her strange suggestion, but it occurred to me that I might not have understood what she really meant. As it turned out, what she had meant was, "I'll knock on your door in the morning so that we can meet for breakfast to discuss the panel we're on." This example of the difference in the meaning of "knock you up" in British and American English shows the complicated situations that can result from cultural misunderstandings. A cultural misunderstanding occurs when something -- a word, gesture, object, social context, or almost anything you can think of -- has a different meaning in two cultures. Sometimes the misunderstandings get _ , sometimes they lead nowhere, and sometimes they can become the starting point of something much more extreme, from love to war. Race is one area where cultural misunderstandings are common. We Americans tend to assume that racial categories are biological rather than social, so it may not occur to us that people from other cultures have a different set of racial concepts and classify themselves and us differently. Some African Americans complain that certain immigrants from other countries, such as Haiti or Jamaica, "act as if they aren't black." The cultural misunderstanding is that, in the immigrants' countries of origin, they would never describe themselves as "black". This doesn't mean that they think they are white. It just means that their cultures have more categories, like marabou or grimaud in Haiti, or fair or brown in Jamaica, than are used in the United States. Meanwhile, white people in America, unaware of this cultural diversity, sometimes refer to all darker-skinned people as "black" without realizing that an issue exists. Resolving cultural misunderstandings can clear the air or even lead to laughter. Sometimes, though, when it comes to race, unidentified cultural misunderstandings can create tension, unhappiness and distrust. We can learn from the passage that cultural misunderstandings  _  .
mostly come from body language are the most serious social problem in the US can cause negative feelings among people can be cleared up with laughter