Bruno A. Cayoun, Bradley Elphinstone, and Alice G. Shires
Traditionally and in modern science, equanimity has been defined as both a practice and the resulting mental state cultivated by this practice. Equanimity is an inseparable component and a central mechanism of action and change in mindfulness practice; requiring exposure to neutral, pleasant, and unpleasant experiences while accepting the experience as it is and preventing the learned reaction (attachment or aversion) to it. Given the interdependence of mindfulness and equanimity, there has been a growing interest for constructing measurement tools to assess equanimity. In response, the Equanimity Scale (ES-16) was developed due to the lack of adequate measures. The development of the ES-16 commenced by identifying a pool of 517 theoretically appropriate items from 26 existing self-report measures of mindfulness and relevant constructs. Following an item selection process by three experienced meditators and teachers specialized in the development of equanimity, 42 items were endorsed as being sufficiently representing equanimity. These reflected two underlying dimensions of equanimity (experiential acceptance and non-reactivity). Studies examining exploratory and confirmatory factor analyses found two factors reflecting these dimensions and supported the reliability of the overall ES-16, and the dimensions of Experiential Acceptance and Non-Reactivity. Research using the ES-16 has provided evidence of concurrent validity through positive correlations with measures of related constructs, such as nonattachment, and negative correlations with measures of psychological distress. The ES-16 was also found to be appropriately sensitive to mental health improvements in clinical settings, where ES-16 scores increased in response to a mindfulness-based intervention, with concordant decreases in self-reported symptoms of anxiety, stress, and depressive symptoms.
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