Social support mediates the effect of morningness on changes in subjective well-being over 6 months.

Studies show that morningness is positively associated with subjective well-being. Our previous research investigated factors that could underlie this relationship, finding that the association between morningness-eveningness and subjective well-being can be partially attributed to the higher levels of perceived social support received by morning-oriented individuals. In the present study, we examine the longitudinal effects of perceived social support in mediating the relationship between morningness-eveningness and subjective well-being. Our results show that this mediating effect remains significant with respect to changes in well-being over a 6-month period. It seems that the causal effect of morningness on well-being may be partially mediated by the causal effect of social support. The findings provide further support for the conclusion that perceived social support is an important contributing factor to the greater well-being reported by morning-oriented individuals. Additionally, our results provide seminal evidence for the causal effect of morningness on well-being.