In addition to individual characteristics, adolescents' individual choices, such as their use of time during nonschool hours, have been found to predict academic achievement. For example, some studies have found that adolescents who are involved in extracurricular activities have higher levels of achievement than those who are not. In an examination of a sample of 1,259 mostly White adolescents, Eccles and Barber (1999) found that adolescents' 10th grade participation in team sports, school leadership or school spirit activities, academic clubs, and performing arts were each independently related to having a higher 12th grade GPA, after controlling for students' gender, verbal and math ability, and parental education. Likewise, Jordan and Nettles (1999) examined the relationship between participation in various out-of-activities in grade 10 and achievement outcomes in math and science in grade 12 in a national sample. They found that adolescents who participate in greater levels of structured activities and adolescents who spend more time alone were both independently associated with higher levels of achievement in math and science in the 12th grade.