The population validity of Erikson's explanation of adolescent identity formation can also be questioned since, much like other psychoanalysts, his theory was grounded on case studies. Although they provide a deep insight into how the human brain may work, using case studies in the development of theories may be open to misinterpretation on the part of the researcher, as the majority of people studied are psychologically abnormal. It could therefore be that the adolescents that Erikson encountered had higher levels of stress, causing him to overemphasise the idea of a crisis.
This emphasis of crisis is disputable. Some would say that it is a time of stress, such as Smith & Crawford (1986) who found that more than 60% of secondary school students reported at least one instance of suicidal thinking, and Csikszentmihalyi* & Larson (1981), whose experiment involving 'bleeping' through pagers found mood swings of adolescents to be much more rapid than those of adults. Others, however, argue that it is not, such as Larson & Lampman-Petraitis (1989) who found no link between the onset of adolescence and increased emotionality. However, the stress as described in the above studies may not be an indicator of a crisis in adolescence, and even then the crisis may not be that of identity formation as suggested by Erikson.
Marcia (1966) produced a theory similar to that of Erikson. He did so by interviewing adolescents going through a crisis, and found that in the formation of identity adolescents may be in any of four 'statuses': identity diffusion, identity foreclosure, moratorium and identity achievement. These statuses depend on two variables: crisis and commitment. Crisis is described as the examination of opportunities and identity issues, and commitment as the extent to which the individual commits to aspirations and other plans for the future. For example, an adolescent who has a wide range of choice open to them, who examines these choices and who succeeds in fulfilling them will have been through a crisis and committed, and is therefore in the identity achievement status; however one which has all of the above choices and yet fails to commit is said to be in moratorium. Although each status is not a prerequisite for the next, moratorium is required in order for identity achievement to be fulfilled.
This theory can be commended for providing an explanation of why adolescents in other cultures and those living in our own culture two centuries ago may experience less of what Erikson would describe as a 'crisis', since there is (or was) less choice about the future. The possibility of such differences also offers an explanation of why some researchers believe that adolescence is stressful and yet some don't (see above), and provides much more flexibility with regard to explaining individual differences, for example why some children in secondary school proceed into college and further education, whereas some enter employment at a relatively early age. Also, there exists research evidence to support Marcia. Kroger (1996) found that those in identity achievement functioned better under stress than those in moratorium, which supports the idea that moratorium is a period of ongoing crisis.
However, there are many methodological criticisms which suggest that the theory may not be entirely valid. For example, the sample was entirely male, and gender differences in the development of identity in adolescence may, and probably do, exist. Additionally, the idea of crisis as seen by Marcia does not take into account emotional or personal factors in identity development, instead paying attention primarily to a choice of career, and might therefore have low construct validity. Internal validity may also be lacking, since the interview technique used by Marcia was to give one-off interviews, which do not provide a good indication of how adolescents change and develop (instead just seeing how they are at one moment in time). Additionally, interviews give qualitative data, so the categorisation of adolescents into the for statuses is a reductionist analysis of this data, especially since it focuses on only two factors in identity development (crisis and commitment).
* chick-sent-ME-hal-yee – I dare you to try and pronounce it right