Recall the following study: Over a 17-year period researchers studied a sample of 707 individuals from a single community. They recorded the number of hours each individual spent watching television during adolescence and early adulthood. In later years, they recorded the number of aggressive acts by individuals in the study.

Science magazine published the results in 2002 in an article titled “Television viewing and aggressive behavior during adolescence and adulthood.”

Which of the following variables could NOT confound the results of this study?

gender
parental supervision and other aspects of family life
poverty and neighborhood conditions
the amount of television the adolescents watch