Gender differences in locus of control have been used to explain gender differences in academic achievement, mental health, income, career status, and so on. However, the findings of gender differences in locus of control are mixed. Some studies found no significant gender differences in locus of control, while others found women had more external locus of control than men. These studies typically have not accounted for extreme response style (ERS) when they generate individual-level locus of control scores based on Likert-scale items. In this way, the estimation of locus of control scores may be distorted, and the observed gender differences in locus of control may be inaccurate. The present dissertation found that a general ERS exists in the locus of control items. Additionally, although controlling for this ERS did not change the gender differences by simply comparing men's and women's locus of control, after controlling for socioeconomic variables, accounting for ERS revealed significant gender differences in locus of control that were not previously apparent.