Being full of oneself is both a benefit and cost growing up as an only child. The job of parents is to maximize the benefits and moderate the costs. Early peer group socializing in daycare may sometimes help an only child develop a more balanced approach to peer relationships when young and for when growing older too.The question was: What is the effect of early day-care on the later social development of an only child? “Would a multi-child environment 5 days a week balance out the effect of high parental attention on weekends in the pre-school period?”Based on counseling contact with only child families and only children over the years, my opinion is that this early socialization can play a helpful role.The “effect” the asker is concerned with “balancing out” is the socially uncontested, exclusive focus on the only child that arises from being the sole recipient of parental attention, the only child actor on the family stage, the one entitled to all the audience applause and investment parents have to give. In consequence, there’s some risk that the young only child’s beneficial self-valuing can become exaggerated self-importance to his or her later cost. To help counter this downside eventuality, consider four possible contributions that early-day care and association with other children can make to the only child’s growth.1) Moving from being used to receiving all of the adult attention as the “one and only child” in the family to pre-school where one treated as “only one of many children” breaks the monopoly on adult attention to which the only child feels accustomed and entitled to at home. This transition enables the only child to become more realistic about less special treatment to be expected and accepted out in the larger world.2) The impulsive rough and tumble of peer group play can help a sheltered only child learn to deal with the push and shove, competition and conflict with others asserting equal importance that he or she is missing out on at home. This experience toughens the only child up to deal with less gentle interactions, to stand up for his or her self-interests, to respect the interests of others, to make friends independent of family, and to socially get along.3) Assuming that there are no signs of “daycare depression” associated with this early separation from family (observable loss of energy, social withdrawal, clinging, anxiety, or despondency), being able to function in a setting away from home and parents, being able to accept other adult authorities who don’t play favorites, being able to enjoy the company of peers, all develop significant strengths. A firm attachment to parents and trusting dependency on them becomes the emotional platform on which more social independence among equals can stand.4) Adequate peer association from a young age can counterbalance the tendency to become so “adultized” (verbally and socially precocious) from exclusive association with parents that the child grows out of social step with peers and has a harder time socially fitting in. While it is to the only child’s great later social advantage to be comfortable relating to adults from his or her childhood, this competence needs not to be at the expense of social comfort relating with those of the same age. An only child needs play with other children to fully experience being a child.The great gift and potential liability of growing up as an only child is turning out feeling extremely full of one’s self. On the positive side, they can like themselves, they can be self-determined, and they can be motivated to do well for themselves. (This is why high self-esteem and drive to achieve are often found to be hallmarks of the only child.) On the negative side, they can be too dedicated to self-interest, they can claim too much consideration in relationships, and they can too often act like they know what’s right and best.Being an only child is a mixed blessing, and that’s okay. Most every human characteristic, no matter how highly valued, is double-edged – it cuts in both advantageous and in disadvantageous ways. Thus the parental challenge here is how to cultivate the beneficial and how to moderate the detrimental that comes with having a single child in the family. Older functioning of the only child is at stake.To be able to establish and maintain committed adult relationships of the loving kind, older only children sometimes need help getting over themselves enough to credit other people’s needs and wants as equally important, to treat contrasting opinions as equally respected, and to settle conflicts over differences by making equitable compromises for the sake of all parties involved. To help meet these ends, I believe adequate early socialization with same age peers in early preschool can be a good place to start.