This paper brings a cross-national perspective to the previously observed relationship between exposure to interpersonal violence in the community during adolescence and later manifestation of psychological distress. Exposure to community interpersonal violence has been recognized as a serious public health problem throughout the world (Krug, Dahlberg, Mercy, Zwi, & Lozano, 2002). Youth have been documented to be by far the most frequent victims of interpersonal violence in the U.S. (Bastian, 1992; Rennison, 2002, 2003; U.S. Department of Health and Human Services, 2001) as well as in other parts of the world such as the Caribbean (Mansingh & Ramphal, 1993; Mercy, Krug, Dahlberg, & Zwi, 2003; Moser & Holland, 1997). Concern about exposure to community interpersonal violence focuses not only on the physical trauma, but also on the psychological trauma that may be a consequence of such exposure (McCann, Sakheim, & Abrahamson, 1988; Rosenthal, 2000). A considerable amount of empirical research on the relationship between exposure to community violence and psychological distress has been carried out within the United States, but no studies of this phenomenon outside the U.S. have been found. Before delving into cross-national and cross-cultural differences in the psychological response to exposure to community violence, however, one should place the phenomenon in a conceptual context.
A meta analysis of the set of 37 independent samples reported in 27 studies published in the U.S. in the 1990s (Wilson & Rosenthal, 2003) established that, in the U.S., exposure to interpersonal community violence during adolescence is moderately related to level of psychological distress manifested later. The analysis also found that the set of 37 independent samples was not homogeneous in terms of the size of the correlations between exposure and distress; that is, some samples produced statistically significantly larger correlations between exposure and distress than did others. The sources of this differential impact of exposure on distress could not be determined from the data available.
This phenomenon of differences in the degree of manifestation of psychological symptoms consequent to exposure to adverse environmental circumstances has been discussed in developmental psychology in terms of the concepts of vulnerability and protective factors (Cowen & Work, 1988; Garmezy, 1991; Howard, 1996; Rutter, 1987). Some individuals may be more sensitive or vulnerable to the effects of exposure to adverse environmental circumstances while others may have characteristics that protect them from the impact. If one pole of a variable is a "protective factor," the other pole of the variable may be considered a "vulnerability factor" (Roosa, Wolchik, & Sandler, 1997). Variables that embody a protective factor at one pole and a vulnerability factor at the other pole are referred to as moderator variables (Baron & Kenny, 1986; Holmbeck, 1997); the presence of the moderator variable moderates or changes the relationship between two other variables depending upon the value of the moderator. Thus, the issue of potential differences between groups in the relationship between exposure to community violence and psychological distress depending upon the characteristics of the group may be framed in terms of protective-vulnerability variables or moderating variables. Differences in levels of psychological distress deriving from exposure to an adverse environmental circumstance may be attributable either to differences in the level of exposure or differences in vulnerability to the adverse circumstance. The contribution of differential level of exposure would be empirically demonstrated by showing that groups that differ in level of exposure also differ in levels of distress. The contribution of differential vulnerability would be empirically demonstrated by showing that one group of individuals had a larger correlation between exposure to a stressor and distress than did another group of individuals. …