We routinely ask students what they do besides study. Usually those who have at least one outside activity are happier and more successful as students than those who do nothing but study. At Cornell and at most other colleges, athletes, for example, often earn higher grades during the semesters of their sport than in the "off" semesters. With more to do, they’re better organized about their work; they’re in better physical shape; and, we think, they are more optimistic and confident about themselves. The old adage about a healthy mind in a healthy body is probably true. As you are well aware, young people have considerable energy and considerable urge to sociability. They need to attend to those physical and social needs.
Cornell has hundreds of organized activities. There is probably a group active in just about any extracurricular interest a student has. And if a student is passionate about a project not already structured into an organized activity, that student can undertake to organize the project her/himself. We've worked with many a small group of students who have set some activity up and passed it on to younger students.
Most students are wisely cautious about extracurricular activities during their first semester. So give your son or daughter some time before quizzing about what he or she is doing. But push a little if, after a term or two your child is engaged in no extracurricular projects. Ask about friendships and happiness. On the other hand, do pay attention to how many activities your student eventually takes on. Most students cannot survive academically with anything like the number of activities they managed in high school. Extracurricular activities do not usually cause lackluster academic performance; they do sometimes mask or excuse lack of academic motivation, confidence, or productivity.