This paper examines how levels of cognitive development affect participants'"adequateness" or ability to function in adventure groups. Twenty-three women who were newly elected or appointed officers of a university campus sorority participated in the study. Prior to the group experience, participants completed a paragraph-completion exercise to assess cognitive level. Large group activities were conducted at the beginning of the day. Then participants were divided into three groups by cognitive level. The cognitive levels reflect three types of cognitive development, i.e., dualism (with a simplistic dichotomy and conformity), transition (beginning to think in more than one way and to question authority), and multiplism (accepting different views). Small group activities consisted of problem-solving situations based on Project Adventure style challenges. Pre- and post-test group assessment indicated that the dualistic thinkers experienced the greatest increase in positive perception of group function. The multiplistic thinkers experienced a small increase. The transition group had the least positive group experience and had a slight decrease in their perception of group effectiveness. Comparison of a self-evaluation scale between groups and across pre-test and post-tests yielded results similar to that of the group assessment. The concept of "adequateness" influences the individual's capacity to understand and cooperate in challenging group activities. (LP)