As a result of public discussions regarding Germany's standing on international rankings of student achievement, increased attention was focused on enhancing cognitive stimulation in preschools. There are some concerns that preschool curricula that focus more on cognitive stimulation rather than on socio-emotional skills might neglect the socio-emotional development of children. These concerns are rooted in the tradition of German preschools focussing more on the stimulation of social than of cognitive skills. This paper examines these claims by drawing on the German preschool programme 'KiDZ' in order to analyse the socio-emotional development (well-being, joy of learning, and worry) of children attending a preschool with a more academically oriented curriculum. This study also investigates effects of domain-specific preschool quality and if any effects of participation in KiDZ might be explained by the quality of the preschools. Positive effects of the children's participation in KiDZ are found and will be discussed. (author abstract)