Introduction
There are considerable individual differences in children’s early dispositional characteristics, such as how they react to challenging situations and their ability to regulate behavioral and emotional reactions.1 These early characteristics serve as a basis for socio-emotional development in childhood and adolescence. It has been found that early dispositional characteristics and socio-emotional functioning have an extensive and prolonged impact on social, school and psychological adjustment. In Western societies, for example, positive emotionality and sociability are predictive of peer acceptance, school achievement and psychological well-being. In contrast, defiance and aggression are associated with later peer rejection, school problems, and other adjustment problems. Finally, social anxiety and behavioral inhibition in infancy and early childhood may contribute to difficulties in peer relationships and adjustment problems of an internalizing nature such as loneliness and depression