researcher susan witt said that parents are the primary influencer on the gender roles of their children. parents, siblings, peers, and even teachers have been shown to react more positively to children engaging in sex-typical behavior and playing with sex-typical toys. this is often done through encouragement or discouragement, as well as suggestions and imitation. additionally, sons are more likely to be reinforced for sex-typical play and discouraged from atypical play. however, it is generally not as looked down upon for females to play with toys designed "for boys", an activity which has also become more common in recent years. fathers are also more likely to reinforce typical play and discourage atypical play than mothers are. a study done by researcher susan witt suggests that stereotypes are oftentimes only strengthened by the environment, which perpetuates them to linger in older life.