Which of the following is TRUE about self-regulation? 

Self-regulation is necessary for the cognitive advances of the preoperational stage. 

Self-regulation makes certain pro-social behaviors possible; these aid overall social development. 

In schools,  self-regulation skills influence students' behavior, but generally not their academic performance (i.e., grades). 

Children who lack good self-regulation skills interact best with other children who also lack self-regulation skills. 

All of these statements are true.