Best Friends, Worst Enemies:  Understanding the Social Lives of Children.  by Michael Thompson & Catherine O’Neill (2001).

Great research-based book with plenty of anecdotes for learning about why friendship is so important for children, the role of gender issues, and how parents can support their children develop strong friendships.

Playground Politics: Understanding the Emotional Life of Your School-Age Child by Stanley Greenspan (1994).

Social Skills of Preschoolers:

Click this link for information on how parents can support their children developing social skills.

http://www.parentingscience.com/preschool-social-skills.html