If an adult wanted to learn to relate to other adults, they would do poorly by attempting to learn from children. If a child wanted to learn to relate to other children, they would most likely learn things by relating to children which they would not learn by relating to adults. Children are behaving inappropriately by adult standards, but they're still learning skills about relating to their peers which will generalize to their experience relating to their peers as adults, which they are unlikely to learn without having peer relationships.