Being an only child is generally considered to be a disadvantage. Absence of siblings is thought to involve the deprivation of critical learning experiences, while the exclusive attention of parents is said to result in overindulgence and overprotection. According to such beliefs, only children develop into selfish, maladjusted and unhappy adults. Various empirical studies have contradicted these beliefs, at least where American adults are concerned. The present study considers adolescent singletons in the Netherlands. It examines the related claims that only children have a less happy youth because they are pressed into adult thinking and behavior too early and that they stand out as "little eggheads"--good at school, but not very sportsmanlike, and unpopular among their peers. Data were gathered by means of questionnaires administered to 2,511 secondary schoolchildren. The only children in this sample neither appeared to be less happy nor was their global self-esteem any lower. The "little egghead" hypothesis was only partly confirmed. Only children feel themselves to be less proficient in sports. However, they do not consider themselves better in school or less popular among peers.