The impact of a sustained stress response on psychological and physical health is well established. However, the moderating role in this relationship of coping, and especially maladaptive avoidance coping, has been hampered by psychometric shortcomings in existing coping scales. Some of these shortcomings include generating items based on theory or face-validity alone, the extraction of too many factors, and the absence of confirmatory factor analytic (CFA) evidence for the obtained structure. This thesis describes the development of a new avoidance coping scale, the General and Specific Avoidance Questionnaire (GSAQ), to address these issues in multidimensional avoidance coping scales in particular.

In contrast to previous scales, the GSAQ items were derived from a scenario technique which elicits responses from participants' experience. Exploratory factor analysis extracted a three-factor solution comprising General, Emotional, and Conflict Avoidance. The scales showed satisfactory reliability, and the structure was confirmed by CFA in independent English and Spanish samples. Concurrent validation and an exploration of differences between high and low avoiders showed that General Avoidance and Conflict Avoidance related to criterion measures in predictable ways, but Emotional Avoidance showed an unexpected pattern.

An analysis of the role of avoidance coping in deliberate self-harm showed no statistically significant effects in a non-clinical university student sample, but the overall trend suggested that self-harmers do, on average, score higher on avoidance coping than non-self-harmers. A subsequent laboratory study introducing research participants to a mild laboratory stressor suggested that individuals who score high on avoidance coping showed greater cardiovascular reactivity compared to low conflict avoiders.

The findings reported in this thesis show that the GSAQ is a reliable tool to use for future research on the role of multidimensional avoidance coping in psychological and physical health.