Ego integrity was the term given by Erik Erikson to the last of his eight stages of psychosocial development, and used by him to represent 'a post-narcissistic love of the human ego—as an experience which conveys some world order and spiritual sense, no matter how dearly paid for'.
Integrity of the ego can also be used with respect to the development of a reliable sense of self, a reliable sense of other, and an understanding of how those constructs interact to form a person's experience of reality; as well as to the way 'the synthetic function of the ego, though it is of such extraordinary importance, is subject...to a whole number of disturbances'.
Erikson wrote that 'for the fruit of these seven stages I know no better word than ego integrity...the ego's accrued assurance of its proclivity for order and meaning'. Erikson considered that 'if vigor of mind combines with the gift of responsible renunciation, some old people can envisage human problems in their entirety...a living example of the "closure" of a style of life'.
The opposite of ego integrity was despair, as 'signified by fear of death: the one and only life cycle is not accepted as the ultimate of life. Despair expresses the feeling that the time is now too short...to try out alternative roads to integrity'.
'Erikson's hypothesis that maturity involves working through a conflict between integrity and despair over past accomplishments' has received some empirical support: on one measure, 'the resolution of past life stages was more predictive of ego integrity than were other personality variables'.
Gail Sheehy termed the later stage of 'Second Adulthood...Age of Integrity (65-85+)'.
The ninth of Loevinger's stages of ego development was the ' Integrated Stage...and ego integrity versus despair are probably Erikson's version of the Integrated Stage'.
In his structural theory, Sigmund Freud described the ego as the mediator between the id and super-ego and the external world. The task of the ego is to find a balance between primitive drives, morals, and reality, while simultaneously satisfying the id and superego. Freudians saw the ego as forming from separate "nuclei": 'A final ego is formed by synthetic integration of these nuclei, and in certain states of ego regression a split of the ego into its original nuclei becomes observable'.