The primary purpose of this secondary analysis was to evaluate the effects of 5-HTTLPR genotype on startle responding. Accordingly, only main effects and interactions relating to 5-HTTLPR genotype are reported here. Results from the entire sample with all variables of interest are presented in Cinciripini et al. (2006). Given the biracial distribution of our sample and possible concerns of population stratification in a mixed racial analysis, we analyzed our data in two ways. First, we conducted separate analyses on each of the racial groups. Second, we analyzed the combined sample, controlling for race and specifically testing for racial interactions. We felt that this second analysis provided more accurate estimates to describe the entire population of smokers.
