A sum of 10 items was used to assess impulsivity at baseline (age 18) and subsequently at ages 25, 29, and 35, respectively. Four of these items (e.g., “I often do things on the spur of the moment”) were drawn from the Eysenck Personality Inventory (H. J. Eysenck & Eysenck, 1968), and the remaining six items (e.g., “I often follow my instincts, hunches, or intuition without thinking through all the details”) were taken from the short-form of the Tridimensional Personality Questionnaire (Sher, Wood, Crews, & Vandiver, 1995). Neuroticism and extraversion were assessed by the Eysenck Personality Questionnaire (EPQ; H. J. Eysenck & Eysenck, 1975) at age 18 and subsequently at ages 25, 29, and 35. The Neuroticism scale includes characteristics such as anxiety, depression, guilt, shyness, moodiness, and emotionality, and the Extraversion scale encompasses lower order traits such as sociability, assertiveness, liveliness, and surgency. Internal consistency, as measured by coefficient alpha, was .79 at age 18, .81 at age 25, .75 at age 29, and .75 at age 35 for the Impulsivity scale1; .85 at age 18, .88 at age
