We conducted two online surveys of a total of 1,258 adults in the United States. Each participant completed a variety of standard questionnaires to measure his or her impulsiveness, ethnocentrism and personal insecurity. (Professors Chua and Rubenfeld describe insecurity as “a goading anxiety about oneself and one’s place in society.” Since this concept was the most complex and counterintuitive element of their theory, we measured it several different ways, each of which captured a slightly different aspect.)Next, the participants completed a test of their cognitive abilities. Then they reported their income, occupation, education and other achievements, such as receiving artistic, athletic or leadership awards, all of which we combined to give each person a single score for overall success. Finally, our participants indicated their age, sex and parents’ levels of education.