Although sharing is a foreign concept for toddlers, many preschoolers are gaining an understanding of and appreciation for the feelings and actions of others. If they are encouraged to share and taught that others are entitled to an equal turn, preschoolers are more likely to ask for a toy politely instead of grabbing, whining, or screaming for it. Caregivers can look forward to less aggressive behavior and calmer play sessions.
Shelov, S. P. (Editor-in-Chief). (2004). Caring for Your Baby and Young Child: Birth to Age 5. The American Association of Pediatrics. Revised edition. New York: Bantam Books.