While individual differences in decision-making have been examined within the social sciences for several decades, this research has only recently begun to be applied by computer scientists to examine privacy and security attitudes (and ultimately behaviors). Specifically, several researchers have shown how different online privacy decisions are correlated with the “Big Five” personality traits. However, in our own research, we show that the five factor model is actually a weak predictor of privacy preferences and behaviors, and that other well-studied individual differences in the psychology literature are much stronger predictors. We describe the results of several experiments that showed how decisionmaking style and risk-taking attitudes are strong predictors of privacy attitudes, as well as a new scale that we developed to measure security behavior intentions. Finally, we show that privacy and security attitudes are correlated, but orthogonal.