Dr. Heussman and his colleagues have designed an experiment to measure whether exposure

Dr. Heussman and his colleagues have designed an experiment to measure whether exposure to violent television is related to children's likelihood of engaging in violent behavior. Children were either exposed to a violent or nonviolent movie clip and then taken into a lab and given the opportunity to hit a doll. Dr. Heussman found that children who watched the violent movie clip were more likely to hit the doll. What is the dependent variable in this longitudinal study?