The traditional definition of race and ethnicity is related to biological and sociological factors respectively. Race refers to a person's physical appearance, such as skin color, eye color, hair color, bone/jaw structure etc. Ethnicity, on the other hand, relates to cultural factors such as nationality, culture, ancestry, language and beliefs.
For example, take the Caucasian race. The physical characteristics of Caucasians were described by M. A. MacConaill, as being "light skin and eyes, narrow noses, and thin lips. Their hair is usually straight or wavy". Caucasoids are said to have the lowest degree of projection of the alveolar bones which contain the teeth, a notable size prominence of the cranium and forehead region, and a projection of the midfacial region. A person whose appearance matches these characteristics is said to be a Caucasian. However, there are many ethnicities within the Caucasian race e.g. Irish, Welsh, German, French, Slovak etc. What differentiates these ethnic groups from each other is their country of origin, language they speak, cultural heritage and traditions, beliefs and rituals.
"Race relations" is one of the dominant themes in American politics from time to time, and refers to relationships between the major race groups - white, black, Latino and Asian. Note that use of the word "Asian" as a race includes a vast variety of ethnicities such as Chinese, Japanese, Korean and Vietnamese. America has also had a sometimes troubled history with ethnic strife e.g. during the waves of Irish and Italian immigration to the U.S. These immigrants were Caucasian but had a different ethnicity compared to the Anglo Saxons who preceded them, and were forced to face ethnic discrimination.
|Definition||An ethnic group or ethnicity is a population of human beings whose members identify with each other, on the basis of a real or a presumed common genealogy or ancestry.||The term race refers to the concept of dividing people into populations or groups on the basis of various sets of physical characteristics (which usually result from genetic ancestry).|
|Significance||Ethnicity connotes shared cultural traits and a shared group history. Some ethnic groups also share linguistic or religious traits, while others share a common group history but not a common language or religion.||Race presumes shared biological or genetic traits, whether actual or asserted. In the early 19th century, racial differences were ascribed significance in areas of intelligence, health, and personality. There is no evidence validating these ideas.|
|Genealogy||Ethnicity is defined in terms of shared genealogy, whether actual or presumed. Typically, if people believe they descend from a particular group, and they want to be associated with that group, then they are in fact members of that group.||Racial categories result from a shared genealogy due to geographical isolation. In the modern world this isolation has been broken down and racial groups have mixed.|
|Distinguishing Factors||Ethnic groups distinguish themselves differently from one time period to another. They typically seek to define themselves but also are defined by the stereotypes of dominant groups.||Races are assumed to be distinguished by skin color, facial type, etc. However, the scientific basis of racial distinctions is very weak. Scientific studies show that racial genetic differences are weak except in skin color.|
|Nationalism||In 19th century, there was development of the political ideology of ethnic nationalism -- creating nations based on a presumed shared ethnic origins (e.g. Germany, Italy, Sweden...)||In 19th century, the concept of nationalism was often used to justify the domination of one race over another within a specific nation.|
|Legal System||In the last decades of the 20th century, in the U.S. and in most nations, the legal system as well as the official ideology prohibited ethnic-based discrimination.||In the last decades of the 20th century, the legal system as well as the official ideology emphasized racial equality.|
|Conflicts||Often brutal conflicts between ethnic groups have existed throughout history and across the world. But most ethnic groups in fact get along peacefully within one another in most nations most of the time.||Racial prejudice remains a continuing problem throughout the world. However, there are fewer race-based conflicts in the 21st century than in the past.|
|Examples of conflict||Conflict between Tamil and Sinhalese populations in Sri Lanka.||Conflict between white and African-American people in the U.S., especially during the civil rights movement.|