... Hedonic wellbeing is mainly seen as comprising the subjective wellbeing components of life satisfaction, positive and negative affect (Diener et al., 1999;Ryan & Deci, 2001). Eudaimonic wellbeing has been proposed to comprise phenomena such as psychological well-being, including self-acceptance, positive relations, personal growth, purpose in life, environmental mastery and autonomy (Ryan & Deci, 2001;Ryff & Keyes, 1995), self-realization, challenge-skill balance, personally expressive activities and pursuit of excellence (Huta & Waterman, 2014;Waterman, 2008), curiosity, engagement, preference for complexity, competence and wellfunctioning (Vitterso, 2013;Vitterso, Soholt, Hetland, Thoresen, & Roysamb, 2010;Vittersø, this volume), social well-being, including social acceptance, social actualization, social contribution, social coherence and social integration (Keyes, 1998(Keyes, , 2013, pursuit of intrinsic goals, living out potentials, autonomy, competence and relatedness (Ryan & Deci, 2001;Ryan et al., 2008;Ryan & Martela, this volume), meaning and use of virtues, strengths (Seligman, 2002(Seligman, , 2011, behaviors such as volunteering, expressing gratitude and persevering (Steger, Kashdan, & Oishi, 2008), orientations and motives such as striving to use and develop best self (Huta & Waterman, 2014), meaning making, and flow (Csikszentmihalyi, 2000;Fave, 2013;Seligman & Csikszentmihalyi, 2000). Substantial variation in term usage, and unclear borders and definitions should not be seen as implying erratic researchers or unmeasurable phenomena. ...