In the social sciences, the term social isolation has two distinct usages. When applied to individuals, social isolation refers to a lack of social ties in general. When applied to social groups, social isolation refers to a lack of social and institutional ties to mainstream society. A group can be socially isolated even if the individuals within the group share a dense network of social ties with one another.
Individual social isolation is a relatively straightforward concept. It can be measured by either the percentage of the population in question that lives alone as calculated from census data or an index of social isolation constructed from survey-based social network data (e.g., the Berkman-Syme index). Given such measurements, researchers in social psychology, gerontology, public health, and many other fields have evaluated trends in social isolation and used standard methods of cross-sectional data analysis to measure the apparent effect of social isolation. This research owes much to the analysis of social isolation and schizophrenia by the Chicago school sociologist Robert E. L. Faris in the 1930s. Social isolation has been found to be a significant risk factor for many health problems and is a particular health issue for the elderly. This literature is often subject to the criticism that the simple relationship between isolation and outcomes may actually be an artifact of some unmeasured third factor (for example, alcoholism may produce both social isolation and heart disease). However, ethnographic and clinical research has also tended to support the idea that individual social isolation matters.
Group-level social isolation has been a key theoretical concept in urban sociology since the publication of William Julius Wilson’s The Truly Disadvantaged (1987), an influential study of troubled innercity communities. Wilson argues that the limited social contact of residents with the institutions of mainstream society is the primary cause of various community social pathologies such as high rates of out-of-wedlock births, welfare dependency, school dropout, crime, and exit from the labor force. Wilson’s later work more explicitly identifies the role of high community rates of joblessness in producing social isolation. In this analysis, macroeconomic changes such as the decline in manufacturing employment combined with the departure of the black middle class from the inner city become the underlying source of inner-city social isolation and social pathology. Wilson’s focus on social isolation is distinct from those theories that trace high rates of innercity social pathology directly to racial discrimination or individual poverty. It is also distinct from “culture of poverty” theories that argue that a substantial proportion of ghetto residents have internalized a pathological set of social values. Wilson’s work has inspired a vast empirical literature on “neighborhood effects” in sociology and in other social sciences. This literature only rarely has aimed to measure group-level social isolation directly; typically it focuses on the relationship between neighborhood-level measures of poverty concentration and various individual or family outcomes.
Wilson’s work has also influenced economists to incorporate social isolation into economic models of inequality. Work in this literature, surveyed by Yannis Ioannides and Linda Datcher Loury (2004), usually combines formal social network theory with microeconomic models of search and matching. Group social isolation is conceptualized here in terms of the properties of a network of connections between individuals, rather than Wilson’s more holistic but difficult to quantify concept of connections between individuals and both institutions and values. One key insight from the economics literature on group social isolation is that group-level isolation, unlike individual-level isolation, is characterized by externalities. That is, a group member who takes costly effort to form social ties with mainstream society will provide benefits to other group members, and these benefits cannot be appropriated by the individual who forms the social tie. As a result, the number of social ties to the mainstream will tend to be inefficiently low.
The closely related concept of social exclusion can be considered a special case of social isolation in which blame is assigned. Brian Barry (2002) notes that “exclusion” implies that the larger society prevents social integration, whereas “isolation” in principle can be voluntary or involuntary and beneficial or malevolent. The concept of social exclusion originated in continental Europe, whereas the notion of social isolation is associated with social scientists based in the United States.
Barry, Brian. 2002. Social Exclusion, Social Isolation, and the Distribution of Income. In Understanding Social Exclusion, ed. John Hills, Julian Le Grand, and David Piachaud. Oxford: Oxford University Press.
Brashears, Matthew E., Miller McPherson, and Lynn Smith-Lovin. 2006. Social Isolation in America: Changes in Core Discussion Networks over Two Decades. American Sociological Review 71 (June): 353–375.
Ioannides, Yannis M., and Linda Datcher Loury. 2004. Job Information Networks, Neighborhood Effects, and Inequality. Journal of Economic Literature 42 (4): 1056–1093.
Wilson, William Julius. 1987. The Truly Disadvantaged: The Inner City, the Underclass, and Public Policy. Chicago: University of Chicago Press.
Brian V. Krauth