On the first day of classes, students in introductory biology courses believe that effort is the most accurate predictor of their academic success. Students know which academic behaviors are important for success, and they are confident that they will earn high grades, attend lectures and help sessions, take advantage of other opportunities to master the course material and raise their grade. Despite this optimism, many students do not follow through on their first-day-of-class expectations, and their grades suffer accordingly. Academic success in introductory science courses is strongly associated with effort-based behaviors, but only weakly associated with aptitude. The relevant research findings are discussed in this chapter relative to how instructors can help students succeed in introductory science courses.