number of weeks that they work. Many have not finished high school. Unable to save money and when retired the working poor depend heavily on their social security pensions to live. Underclass (Typical Income $15,000) These people are under-employed. They suffer from low education, low employability, and/or low income. Some can not work because of their age or disability. Hard times might be magnified because they belong to a minority group who suffers discrimination in the workforce. Although the social hierarchy is most obvious at the extremes, differences between classes begin to become blurred when moving away from one of the extremes and towards the centre to where the middle and working classes are. It is difficult to get a precise classification. See also Social stratification References Further reading Gilbert, Dennis. American Class Structure. 10th ed. Los Angeles: Sage, 2018). Lareau, Annette. Unequal Childhoods: Class, Race, and Family Life. 2nd edition. Berkeley: University of California Press, 2011. Social classes Sociological theories