Developmental disorders（DD）are now so common that it is even more necessary to investigate the relationship between DD and personality disorders（PD）. Despite the lack of studies, DD and PD have much in common. For research on personality and its disorders, direct, real‒time observation by researchers themselves on the“black box”of temperament and its interaction with the environment is needed. For research on DD, especially in those with mild DD symptoms, how developmental characteristics and their interaction with the environment affect the personality in adulthood should be investigated.