that individual behavior cannot be accurately analyzed apart from the social and cultural structures in which it is embedded.
At the broadest level, social conditions, such as the lack of universal access to health care, racial and ethnic discrimination, unemployment, and lack of public monies to promote AIDS prevention, contribute to a social context in which HIV transmission is prone to occur. For example, the continuing high unemployment rate among African American men (45 percent) fuels the appeal of the illegal drug trade as an alternate means of support, which in turn creates an environment that fosters drug use. Yet unemployment is not often represented as integral to the high rate of injection drug use among African American men and the subsequent transmission of HIV (Schneider, 1992). Similarly, the lack of access to health care among many low-income and racial and ethnic groups means that many cases of HIV infection never reach the attention of the medical community for diagnosis and treatment, thereby ensuring both an underestimation of the AIDS epidemic in certain populations, and its spread to other group members. Unfortunately, then, current health care arrangements make it likely that those populations most affected by HIV are those least likely to receive the preventive care needed to stem its spread. To effect change in the social arrangements at this level requires federal policy initiatives of broad scope as well as changes in the public's prevailing attitudes and mores. Both of these can be influenced by better knowledge about the structures of social life that affect the transmission and prevention of HIV. One important structure in this regard is the social network.
A social network is composed of an individual's relationships in the immediate social world; the number and type of relationships and the degree of closeness among those relationships are part of the structure of that network. Thus, networks are an indicator of social integration—how extensively and how tightly one is woven into the fabric of social life. Social networks are a source of emotional and instrumental support, providing companionship, information, and reference groups. Both the content (e.g., friendship, professional) of the interactions in the network and the form or structure of the network itself (e.g., close knit or loose; extensive or limited) can affect behavior profoundly. Recent research using network analysis suggests that the social network may be highly amenable to specific intervention efforts.