ABSTRACT
Socio-economic status (SES) is generally defined in terms of social class or occupational status, there being considerable overlap between the two definitions. When people are classified according to social class, the major distinction is between whether they carry out professional and white collar work on the one hand, or skilled and unskilled manual work on the other. This distinction corresponds broadly to that between the middle class and the working class; a distinction that implies marked differences in life style, aspirations, economic security and political affiliations. These two broad categories are usually further subdivided to provide a rough five or six point scale. In spite of its simplicity, the scale provides a valid index of many aspects of SES. Survival is thought to play the major role in many animal populations and primitive human societies.
