Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Erik Erikson (1902-1994) became one of the earliest psychologists to take an explicit interest in identity. The Eriksonian framework rests upon a distinction among the psychological sense of continuity, known as the ego identity (sometimes identified simply as "the self"); the personal idiosyncrasies that separate one person from the next, known as the personal identity; and the collection of social roles that a person might play, known as either the social identity or the cultural identity. Erikson's work, in the psychodynamic tradition, aimed to investigate the process of identity formation across a lifespan. Progressive strength in the ego identity, for example, can be charted in terms of a series of stages in which identity is formed in response to increasingly sophisticated challenges. The process of forming a viable sense of identity for the culture is conceptualized as an adolescent task, and those who do not manage a resynthesis of childhood identifications are seen as being in a state of 'identity diffusion' whereas those who retain their initially given identities unquestioned have 'foreclosed' identities (Weinreich & Saunderson 2003 p7-8). On some readings of Erikson, the development of a strong ego identity, along with the proper integration into a stable society and culture, lead to a stronger sense of identity in general. Accordingly, a deficiency in either of these factors may increase the chance of an identity crisis or confusion (Cote & Levine 2002, p. 22).
Who was one of the earliest psychologists to take an explicit interest in identity?