The United States is a culturally diverse nation, home to a wide variety of ethnic groups, traditions, and values. The culture held in common by the majority of Americans is referred to as "mainstream American culture," a Western culture largely derived from the traditions of Western European migrants, beginning with the early English and Dutch settlers. German, Irish, and Scottish cultures have also been very influential.[6] Certain Native American traditions and many cultural characteristics of enslaved West Africans were absorbed into the American mainstream. Westward expansion brought close contact with the culture of Mexico, and large-scale immigration in the late nineteenth and early twentieth centuries from Southern and Eastern Europe introduced many new cultural elements. More recent immigration from Asia and especially Latin America has had broad impact. The resulting mix of cultures may be chraacterised as a homogeneous melting pot or as a pluralistic salad bowl in which immigrants and their descendants retain distinctive cultural characteristics. ----------------------------------------------- While American culture maintains that the United States is a classless society,economists and sociologists have identified cultural differences between the country's social classes, affecting socialisation, language, and values. The American middle and professional class has been the source of many contemporary social trends such as feminism, environmentalism, and multiculturalism. Americans' self-images, social viewpoints, and cultural expectations are associated with their occupations to an unusually close degree.While Americans tend to greatly value socioeconomic achievement, being ordinary or average is generally seen as a positive attribute.Women, formerly limited to domestic roles, now mostly work outside the home and receive a majority of bachelor's degrees.The changing role of women has also changed the American family. In 2005, no household arrangement defined more than 30 percent of households; married childless couples were most common, at 28 percent.The extension of marital rights to homosexual persons is an issue of debate, with more liberal states permitting civil unions and Massachusetts recently having legalised same-sex marriage.