In an adolescent social system in which academic achievement is highly valued, those who achieve highly will include more people whose actual intelligence is high that in a social system where this activity is less valued. This is one hypothesis about the possible effects that adolescent value systems have upon education, and it is examined here, using ten schools with differing value systems. After this examination, the question of what is the source of these value systems is asked, and evidence is presented suggesting an apparently powerful effect of interscholastic athletics. This result raises questions about the general effect of interscholastic competition of other sorts on the adolescent value system of a school.