 Peer groups, whether intentionally or unintentionally, exert peer pressure and operant learning principles to shape behavior through reinforcement, resulting in members of peer groups become increasingly similar over time.Many adolescents report the effects of peer influence on many aspects of their behavior, including academic engagement, risk-taking, and family involvement; however, the direction of this influence varied dependent on the peer group the adolescent was affiliated with.The assessment of social emotional development in young children must include an assessment of both child-level factors, such as genetic disorders, physical limitations, or linguistic and cognitive developmental level, as well as contextual factors, such as family and cultural factors.