Children's sense of self develops during middle childhood. Their self-concept and self-esteem change as they evaluate their competencies compared to peers. Children also develop greater self-control over impulses as their ability to delay gratification increases. Peer influence also grows in importance. Schools play an important role in development, though television and digital media now occupy much of children's leisure time, which can impact development both positively and negatively depending on content and how actively children engage with different media. Stress from life events like divorce or abuse can also differently impact children depending on their sex, age, and temperament.