SOCIAL CAPITAL

Social Capital

Social Capital

Part A: Literature Review on Social Capital

As a possible determinant of population health, social capital has emerged as a topic of growing interest in the epidemiologic literature. Epidemiologic studies have explored the potential protective effects of social capital on a variety of health outcomes (Putnam, 2006). This entry highlights the conceptualization of social capital, hypothesized mechanisms for its health effects, and features of the empirical evidence on the relations between social capital and health to date, including the measurement of social capital (Portes, 2008).

Unlike financial capital, which resides in people's banks and in property, and human capital, which is embedded in people's education and job skills, social capital has been conceptualized to exist in people's relations to one another—that is, within social networks (Lin, 2008).

Conceptualizations of social capital have ranged from definitions focusing on the resources within social networks that can be mobilized for purposeful actions to definitions that encompass both social structures and associated cognitive resources such as trust and reciprocity (Kim, 2006). In addition to being categorized according to structural and resource characteristics, social capital has been dichotomized into many forms, including formal versus informal social capital (e.g., participation in labor unions vs. family dinners), inward-looking versus outward-looking social capital (e.g., chambers of commerce vs. the Red Cross), and bonding versus bridging social capital (Kawachi, 2008).

The distinction between bonding social capital and bridging social capital has probably gained the most prominence in the social capital and health literature. Bonding social capital refers to social capital within relationships between individuals with shared identities such as race/ethnicity and gender, whereas bridging social capital corresponds to social capital in relationships between individuals who are dissimilar (Putnam, 2006).

There is ongoing debate among social capital scholars as to the extent to which social capital is primarily an individual-level social network asset (i.e., dwelling within individuals' family and friend relationships), a collective or public good, or both. Furthermore, not all social capital can be considered an unqualified benefit for all (Portes, 2008). The sociologist Alejandro Portes recognized the potential for 'negative externalities' of social capital that could harm individuals outside of a group, yet produce benefits, or 'positive internalities,' for group members. For example, among residents in a predominantly African American, racially segregated neighborhood, individuals may experience positive effects from their relationships with one another but suffer negative consequences from discriminatory practices by outside individuals of other races/ethnicities (Lin, 2008).

Several mechanisms by which social capital may affect health have been proposed. These include the diffusion of knowledge about health promotion, influences on health-related behaviors through informal social control, the promotion of access to local services and amenities, and psychosocial processes that provide support and mutual respect (Kim, 2006).

Each of these mechanisms is plausible based on separate theories and pathways. First, through the theory of diffusion of innovations, it has been suggested that innovative behaviors diffuse much faster in communities that are cohesive and high in trust. Informal social control may also exert influence over such health behaviors (Kawachi, ...