Unlike the more commonly studied topic of egocentrism, which focuses on cognitive-developmental barriers to effective social functioning caused by young children's inability to appreciate others' perspectives, the concept of selfishness emphasizes motivational barriers to effective social behavior caused by an individual's unwillingness to balance self-enhancing and other-enhancing goals in situations calling for cooperation, sharing, or consideration for others. Indeed, the term selfishness is generally considered inappropriate for self-centered behavior that can be attributed to ability deficits. That is why this label is rarely used to describe the social behavior of infants and young toddlers who have not yet developed certain rudimentary social-cognitive and social-emotional capabilities. In contrast, as children approach adolescence, the failure to balance powerful self-interests (e.g., autonomy, material gain, emotional gratification, social superiority) with the interests of others can increasingly be attributed to weak integrative motives (e.g., lack of concern for others' welfare or norms of social responsibility).
Damon, William. Greater Expectations: Overcoming the Culture of Indulgence in Our Homes and Schools. New York: Free Press, 1996.
Ford, Martin. "Motivational Opportunities and Obstacles Associated with Social Responsibility and Caring Behavior in School Contexts." In J. Juvonen and K. Wentzel eds., Social Motivation: Understanding Children's School Adjustment. New York: Cambridge University Press, 1996.