In fact, teachers often implement PML activities with the assumption that children already possess the social skills needed to collaborate productively with peers. However, it may be erroneous to assume that all or even most children possess such skills. Substantial differences exist in children’s pre- paredness to relate and work with classmates because social competencies are not universally taught (Ladd, 2005). Even socially adept children may need to develop new or specialized skills to work effectively with different types of partners.