| The present study empirically validates a six-dimensional nonlinear dynamical system of stress and coping originally presented by Neufeld (1999). The system casts verbal conjectures regarding the dynamic, transactional, and systemic nature of stress and coping in a formal mathematical framework. Dimensions include level of exogenous stressors impinging on the system, level of stress arousal, cognitive efficiency, level of coping in the form of decisional control, sensitivity to increases in levels of exogenous stressors and responsiveness of coping outlay to changes in exogenous stressor level. Time series data was collected by having participants (n = 20) complete a daily diary for 60 consecutive days. The daily diary was designed to tap into each of the six relevant system dimensions. Model fit was assessed using both nonlinear dynamical methods as well as more traditional statistical tests. Significant fit between model and observed trajectories was found for 12 out of 20 participants using dynamical model fitting techniques and 15 out of 20 participants using correlational analyses. To further validate the model, a set of surrogate data was generated by temporally reordering the observed trajectories for 10 of the participants. The fit between surrogate and observed trajectories was then compared to the fit between model and observed trajectories. For the majority of participants, the model outperformed the surrogate data in tests of model fit, lending further support to the validity of the six-dimensional model of stress and coping. Limitations discussed include deciding which entities to include in a theoretical model, difficulties operationalizing and measuring key constructs, and the relatively limited number of numerical methods which have been developed to analyse nonlinear systems. Implications for both the stress and coping literature as well as the field clinical psychology are discussed. It is concluded that the utility of a formal, dynamical systems approach to the study of stress and coping, as illustrated through the empirical instantiation of the present six-dimensional model of stress and coping, outweighs the potential costs of embracing such a mathematically sophisticated approach. |
