When students apply for college admission, they are asked to list their extracurricular involvement between grades 9 and 12. Students who have not been involved in activities in high school are assumed to be students who will not be involved on campus in college either. That makes them less attractive to colleges.
Often students are less active in high school organizations because they are shy and don't see a reason to make the extra effort to be involved. Tell your teen that being active in student organizations in high school will have an effect on getting into college. Also let your teen know that no involvement or limited involvement in clubs could keep him or her out or the National Honor Society in high school even if grades are fantastic.
Take a look at clubs at your teen's high school and suggest some that could be considered for next year. High grades and test scores are wonderful but involvement in student activities is also a key to good outcomes when students apply to college.