“…Vitttersø and colleagues have published a number of papers delineating the differences between eudaimonia and hedonia (e.g. Vittersø, 2003;Vittersø, Oelmann, & Wang, 2009;Vittersø, Søholt, Hetland, Thoresen, & Røysamb, 2010), and although space does not permit an in-depth review of each, one of Vittersø's most recent investigations will be discussed. Vittersø proposed that the subjective states of hedonia and eudaimonia serve distinct functions, with eudaimonia (which he operationalizes as feelings of interest and engagement) considered important whilst pursuing complex goals and when conducting challenging activities, and hedonia (which he operationalizes as feelings of pleasure and satisfaction) considered important for the preservation of stability and for rewarding need fulfilment.…”