Personality Development

There has been considerable interest in the multiple birth status of twins as to the effect of twin status, and particularly identical versus fraternal status of twinship, on personality development. There has been less opportunity to study these effects on the personality development of multiples beyond twins. Twin reports are suggestive that twin status does have some influence on personality development. Ainslee has identified several stress points in the life of twins for the development of identity. Rorschach studies of monozygotic twins have generally shown greater similarity between monozygotic twins than for dizygotic twins. A Rorschach assumption is that the human movement (M) represents for the child a recreation of his object world. The Blatt Scale of Object Representations measures the differentiation, accuracy, level of integration, motivation, congruence of action, affective benevolence or malevolence of action, and activity level of the human or quasi-human responses on the Rorschach.