Nonsocial Activity Children
Next Comes Parallel Play
Associative Play
Cooperative Play
First Friendships
Conflicts Do Arise..
Make-Believe Play
Parents Influence Peer Relationships
Direct Parent Influencing
And Indirect Parent Influencing
Additional Resources..
http://www.ericdigests.org/pre-923/peer.htm
http://eric.ed.gov/?id=ED435496
http://www.pbs.org/parents/education/going-to-school/social/laws-of-friendship/