Purpose: Working from lifespan development theory and the theory of Selective Optimization with Compensation (SOC), I provide theoretical analyses to inform and direct research on Taijiquan where research questions involve issues of adaptive development (optimization of gains, maintenance of function, and prevention of lost resources). I also used these frameworks to construct a biopsychosocial mind-body practices model that seeks to explain and predict the role of key aspects (curriculum, practice, context) in Taiji-related development. The above frameworks are further substantiated through a comparative analysis of health status between Taijiquan practitioners (N =120; age range = 24-83, M = 54.77) and a nationally representative sample (N = 414,629; age range = 18-99, M = 54.86) collected by the Centers for Disease Control and Prevention (CDC). The model's predictive potential is explored through an analysis of health status within a subset of experienced Taiji practitioners (N = 94; age range = 24-83, M = 55.82). Design: Theoretical and cross-sectional; between- and within-group comparisons. Methods: Responses from a convenience sample of Taiji practitioners were collected using an online survey. The instrument was designed to collect data on health-related quality of life (HRQoL), lifestyle variables, and Taiji practice regimens. Data from Taiji practitioners were merged with the CDC's 2008 Behavioral Risk Factor Surveillance System (BRFSS) dataset, forming three groups: no exercise, some exercise, and Taiji exercise. Health status was regressed on exercise group while controlling for age, income, and education, as well as the interaction between age and exercise group. Further analyses were also conducted on a subset of the Taiji data (N=94). These analyses examined the relationships among self-reported health, practice regimens, and diet while controlling for age and experience. Results: In the first set of analyses (see paper one), I controlled for the effects of age, income, education, and the differential effects of age on exercise group, while determining associations between health and group membership. A significant interaction effect (p < 0.001) occurred between age and exercise group membership. This interaction showed little difference between exercise groups in the young adult age range, but among older adults, Taijiquan practitioners displayed the best HRQoL. In the second set of analyses (see paper 2), I found significant interaction effects between (a) curricular complexity and out-of-class practice (p < 0.05) and (b) curricular complexity and diet (p < 0.05). Conclusions: The extraordinary health status trajectory among Taiji practitioners may be attributable to several conditions including: (a) the implied presence of SOC-related strategies, (b) the general benefits of psychophysical expertise, and (c) concomitant structure between Taiji-related goals and health behaviors that contributes to optimal aging. Specifically, intervention designers, Taiji teachers, and practitioners should consider the potential benefits of well rounded Taiji curricula, regular out-of-class practice, and healthy diet for optimizing health-related gains and minimizing losses typically associated with aging. / Ph. D.