text: Erikson, Erik - Pioneering PSYCHOANALYST, much interested in the development of the person throughout the lifespan, rather than simply during childhood. In this respect he differed from other influential theorists such as Sigmund FREUD and Jean PIAGET. Erikson argued that there existed "eight ages of man", each of which had its own characteristic "crisis" (a term which he used in a less negative sense than one might naturally understand it. The crisis of the infant up to the age of eighteen months, for instance, is trust/mistrust of the primary caretaker (usually the mother); the crisis of the "later years" is integrity vs. despair. Particularly influential is Erikson's theory of adolescence, which he believed to be characterised by integrity vs. role confusion. Although many of Erikson's theories have been influential, they have nevertheless also been criticised for their unproveability.