Sharing is a friendly thing to do but younger children tend to not share as well. There identity is focused on themselves as the center and interactive games with other children are less likely than playing along side each other each with their own toy. If squabbles occur than distracting with a new activity rather than punishing may be more effective with toddlers. Older children may be better at sharing toys and playing a game or make believe role playing activities together. Play helps children practice for later adult roles. Going to work, teaching the class, pouring pretend tea for a tea party of stuffed animals to pretend drink are all preparing the child for the real tasks later in life.
The book NurtureShock by Po Branson and Ashley Merryman includes a description of a role playing in a preschool setting that helped improve the children's school abilities in many ways. The main difference the program used from other types of play or classroom activity was in having the children plan their play role activity in advance, who will be the teacher or the principal or the school nurse or the student and what event are we going to pretend to be doing. Then the activity was role played for most of an hour. The strategy seemed to help with planning and communication and self control abilities. (NurtureShock)
Disclaimer: Opinions are my own and the information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes.