"My son has been a class clown and it sort of ran in the family"

This quote by Robert Klein suggests that his son tends to be a class clown, and that this characteristic is something that is passed down in his family. It suggests that this habits is something that is viewed as regular and accepted in his family, and that it is a quality that is shared by a lot of its members. It might also be translated as a sign of love and pride in his kid, as he takes pride in his child's ability to make people laugh and bring joy to the classroom. It might also be viewed as an alerting to other parents, as it recommends that this behavior can be passed down from generation to generation, which it is very important to be aware of this when raising kids.