Social cognitive career theory (SCCT) defines self-efficacy as the critical variable that influences the development of career-related beliefs and attitudes, including interest. In comparison, the authors propose that J. L. Holland’s (1997) theory of Realistic, Investigative, Artistic, Social, Enterprising, and Conventional (RIASEC) types can be interpreted as supporting an alternative model in which both interest and self-efficacy are components of an individual’s vocational identity. Meta-analytic research indicates that RIASEC-based measures of interest and self-efficacy are positively correlated, but these results are also interpreted as supporting the distinctness of the two constructs. The present study evaluates links between interest and self-efficacy with occupation- and activity-based measures of interest and self-efficacy. Multidimensional scaling, cluster analysis, and structural equation modeling results suggest that observed correlations between interest and self-efficacy measures can be attributed to shared Holland-type characteristics of the measures. These results support a Holland-based integrated model of individual differences, with both interest and self-efficacy indicators of RIASEC types, thereby raising questions about the ordering of self-efficacy and interest measures in the SCCT model but also highlighting the importance of assessing both constructs in applied settings.