1. an individual’s sense of self defined by (a) a set of physical, psychological, and interpersonal characteristics that is not wholly shared with any other person and (b) a range of affiliations (e.g., ethnicity) and social roles. Identity involves a sense of continuity, or the feeling that one is the same person today that one was yesterday or last year (despite physical or other changes). Such a sense is derived from one’s body sensations; one’s body image; and the feeling that one’s memories, goals, values, expectations, and beliefs belong to the self. Also called personal identity.

2. in cognitive development, awareness that an object is the same even though it may undergo transformations. For example, a coffee cup remains the same object despite differences in distance, size, color, lighting, orientation, and even shape. Also called object identity.