Whole systems of complementary and alternative medicine (WSCAM) emphasize positive emergent outcomes for the patient, for example, a sense of well-being. This paper presents a questionnaire-based study in healthy young adults for the purpose of exploring individual differences that contribute to the sense of well-being and to identify characteristics of flourishing versus nonflourishing individuals in terms of nonlinear dynamical systems concepts.Young adult college students (N = 856) completed questionnaires assessing global well-being (Arizona Integrative Outcomes Scale [AIOS]), global physical health, positive and negative mood (Positive and Negative Affect Schedule [PANAS]), resilience (Connor- Davidson Resilience Scale), and repressive defensiveness. Next, subjects were divided into flourisher/languisher groups by a previously determined ratio of positive/negative scores established by a study using complex systems methods.Positive-to-negative affect (P:N) ratio accounted for more variance in AIOS (R 2 = 0.19; P < .001) than did separate positive or negative PANAS scores or physical health. Flourishers (14.5% of the sample) were significantly higher than languishers in defensiveness and resilience.Positive-to-negative affect explains a substantial portion of the variance in well-being of healthy young adults. The low percentage of flourishers in this nonclinical sample is consistent with previous population-based studies and suggests that flourishers are a minority, even in nonclinical settings. Positive-to-negative affect may be a useful variable for subsequent prospective studies of applied WSCAM treatments and in well and clinical populations. The well-being measure used in this study is easy to complete, sensitive, and may be a useful clinical measure to track change with treatment over time.