Developmental Psychology 1993, Vol. 29, No. 5, 893-906 Copyright 1993 by the American Psychological Association, Inc. Developmental Range of Reflective Judgment: The Effect of Contextual Support and Practice on Developmental Stage Karen Strohm Kitchener, Cindy L. Lynch, Kurt W Fischer, and Phillip K. Wood In this study of K. W Fischer's (1980) skill theory and the development of reflective judgment (K. S. Kitchener & P. M. King, 1981), 156 students, 14-28 years old, were tested. Two thirds responded to the Reflective Judgment Interview (RJI) and the Prototypic Reflective Judgment Interview (PRJI) twice, with the 2 administrations approximately 2 weeks apart. The remaining one third were tested at 2-week intervals only on the RJI. The PRJI was designed to provide support for optimal level reflective judgment responses, whereas the RJI measured functional level. Ss scored signifi- cantly higher on the PRJI than they did on the RJI at both testings, and there was a significant age effect on both measures. Age differences on the 2 measures could not be statistically accounted for by a measure of verbal ability. The PRJI data also provided evidence for spurts in development between ages 18 and 20 and between ages 23 and 25-26. In reaction to earlier claims of Inhelder and Piaget (1958) that formal operations are the pinnacle of intellectual development, thefieldof adult cognitive development has focused on showing that formal operations are an inadequate account of the cogni- tive abilities of adults (Basseches, 1984; Kitchener, 1983; Kuhn, 1989), that the tasks used to investigate formal operations have little relevance to the problems adults face (Wood, 1983), and that few adults actually score as formal operational on Piagetian tasks (King, 1986; Niemark, 1979). As a result of these apparent deficiencies, several neo-Piagetian models have been postu- lated (Basseches, 1984; Fischer, 1980; Kitchener & King, 1981; Richards & Commons, 1984). However, empirical testing of these models remains in its infancy, and only a few attempts have been made to evaluate relations between models (Benack & Basseches, 1989; Commons et al, 1989; King, Kitchener, Wood, & Davison, 1989). Similarly, although environmental variables have been found to play an important role in the exhibition of cognitive skills in children (Flavell, 1985), little has been done to evaluate the role of environmental variables in adolescent and adult perfor- Karen Strohm Kitchener and Cindy L. Lynch, School of Education, University of Denver; Kurt W Fischer, Graduate School of Education, Harvard University; Phillip K. Wood, Department of Psychology, Uni- versity of Missouri. Earlier versions of this article were presented at the meetings of the American Educational Research Association in March 1989 and the American Psychological Association in August 1989. It is based in part on a dissertation titled The Impact ofa High Support Condition on the Exhibition ofReflective Judgment (University of Denver, Denver, Colo- rado, 1989) by Cindy L. Lynch. We wish to express our gratitude to Cathy Kasala, Patricia M. King, Marcia Middel, and Christina Whitmire for their help in carrying out the study, to the Spencer Foundation for its financial support, and to the reviewers of this article for their insightful comments and sugges- tions. Correspondence concerning this article should be addressed to Karen Strohm Kitchener, School of Education, University of Denver, 2450 South Vine Street, Denver, Colorado 80208. mance on the tasks designed to measure development accord- ing to these neo-Piagetian models. What has been done sug- gests that such variables cannot be ignored (Fischer & Kenny, 1986; Irwin & Sheese, 1989; Rest, 1973). The primary purpose of this study was to test the predictions of one model, skill theory (Fischer, 1980), for another, reflec- tive judgment (Kitchener & King, 1981), particularly in terms of the influence of different contextual conditions on the stage or level of performance (see Table 1). Fischer (1980; Fischer, Bullock, Rotenberg, & Raya, 1993) has argued that seven gen- eral skill levels emerge between age 2 and age 30; however, he also argued that no skill exists independent of the environment, and thus, no individual can be said to be at a single developmen- tal level. Rather, an individual's competence will vary depend- ing on the conditions under which it is assessed. The degree to which environmental factors (such as memory prompts, prac- tice, and the nature of the task) support high-level performance is a primary determinant of observed variation in the range of scores (Lamborn & Fischer, 1988). One of the most powerful factors, called contextual support, involves the prompting of a skill. With such support the individual shows a relatively high developmental level, but without the support performance drops, even after a short period of time. Fischer (1980) called performance without contextual support functional level, and he noted that it shows substantial variation across d6mains. It marks the low end of the developmental range. Fischer (1980) contrasted functional level to optimal level, the highest level that the individual can consistently produce under conditions that provide high levels of contextual support and opportunities for practice (Lamborn & Fischer, 1988). Even with contextual support and other environmental factors sup- porting high performance, individuals will show an upper limit —their optimal level—beyond which their performance will not go when they are engaged in independent problem solving. That is, they will fail at all tasks that are more complex than their optimal level. Fischer and his colleagues (Fischer & El- mendorf, 1986; Fischer, Hand, Watson, Van Parys, & Tucker, 1984; Lamborn & Fischer, 1988) have identified this develop- mental range in several domains in studies with children. 893