Judith Harris's group socialization theory has received a lot of attention in the media: parents supposedly do not play an important role in shaping the personality development of their children, but peers do. On closer examination, research findings indicate that the importance of parents is limited indeed. As yet, however, there is no conclusive evidence that peers do indeed have a lasting influence on personality. Nevertheless, it might be refreshing to interpret diagnosis, treatment and prevention of personality disorders using the group socialization theory.