Attitude strength is a meta-attitudinal characteristic that reflects an attitude's durability, impactfulness, or both. Studies on the social origins of attitude strength are scarce and have focused on the effects of social support. These studies have documented that social support increases attitude strength. Social support, however, is only one dimension of social context. Among additional dimensions of social context, social power is especially important. Social power refers to the amount of control one group has over its own fate and the fate of outgroups. Although sometimes related, social support and social power refer to different underlying processes. Thus, their effects on attitude strength warrant examination. In particular, the effects of power are of special interest because of the ubiquity of power differentials among individuals and groups. The goal of my thesis was simply to examine both the unique as well as combined effects of social support and social power on eight indicators of attitude strength (clarity, correctness, certainty, confidence, ambivalence, importance, vested interest, and latitude of rejection). I hypothesized the following: (1) the main effect of social power would resemble the main effect of social support in that high social power would strengthen attitudes (2) social support and social power, when combined and similarly valenced, would have the greatest effects on attitude strength (3) the effect of social support (social power) in the absence of social power (social support) would differ for different indicators of strength. Specifically, high social power in the absence of social support would increase vested interest, thus strengthening attitudes, as well as narrow latitude of rejection, thus weakening attitudes. These hypotheses were examined in a 2 (social power: high vs. low) X 2 (social support: high vs. low) study with social power operationalized as control over others in a simulated work situation and social support operationalized as others' agreement with a participant on an important social issue. One hundred seventy students, recruited from the Psychology subject pool, responded to attitude strength measures after being randomly assigned to experimental conditions. A MANOVA revealed a significant main effect for social support, F (1, 124) = 2.46, p < .05, but not a significant main effect for social power, F (1, 124) = .43, p = .882, nor a significant interaction effect of Social Support X Social Power, F (1, 124) = .797, p = .592. Most trends, however, were in the expected direction. Implications for strengthening of attitudes in the social context are discussed.