Abstract
Concentration and tranquility usually co-arise with mindfulness during mindfulness practice and in daily life and may potentially contribute to mental health; however, they have rarely been studied in empirical research. The present study aimed to examine the relationship of concentration and tranquility with mindfulness and indicators of mental health. With no existing self-report measure assessing concentration and tranquility, the Concentration Scale and Tranquility Scale were first developed and validated. Items were developed based on the extant literature, rated by a group of experts, and selected according to their ratings. Exploratory factor analyses (EFA; n = 384) and confirmatory factor analyses (CFA; n = 384) were employed in separate samples of university students and community adults to establish the factor structure of both scales. Their construct validity was established in another similar sample (n = 333) by examining their correlations with variables including (a) concentration-related concepts, (b) tranquility-related concepts, (c) mindfulness-related concepts, and (d) perceived stress and psychological distress. The relationships between concentration, tranquility, mindfulness, perceived stress and psychological distress were then examined by hierarchical multiple regressions, both cross-sectionally and longitudinally. A single-factor structure was found by the EFA and confirmed by the CFA for both scales. Concentration and tranquility were significantly and positively associated with (a) attentional control and (b) mindfulness and nonattachment; and negatively associated with (c) irritability and (d) perceived stress and psychological distress. Concentration and tranquility were found to have a significant incremental value over the effect of mindfulness on indicators of mental health. Concentration and tranquility can incrementally explain mental health above and beyond the effect of mindfulness.