Inconsistent responding to repeated MMPI items: is its major cause really carelessness?

Previous authors have recommended using the number of inconsistent responses given to repeated MMPI items as a measure of the carelessness with which an individual has responded to the test. Such a recommendation assumes that a respondent who reads the items carefully must necessarily give an identical response to both presentations of the same item. Contrary to this assumption of a single cause, three potential causes of inconsistency--maladjustment, carelessness, and indecision--were investigated among 202 normal undergraduates who responded to the whole MMPI twice. The results suggest that indecision may be a more important cause of inconsistency than carelessness, thereby calling into question the use of inconsistencies on repeated MMPI items as a "carelessness" scale. Implications regarding the processes involved in responding to personality items are discussed.