We administered the 60-item scale, which measures the personality traits of neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness (Costa & McCrae, 1997). We analyzed the extraversion and conscientiousness subscales, as high extraversion and low conscientiousness were a priori hypothesized to be most relevant to the construct of impulsivity under study here. Sample items from the extraversion scale include ‘I like to have a lot of people around me’ and ‘I like to be where the action is’. Sample items from the conscientiousness scale include ‘I’m pretty good about pacing myself so as to get things done on time’; ‘I am not a very methodical person’ (reverse coded).
