Are you thinking about friends or money? Spontaneous thought contents reveal the value of social relationships for happiness

Spontaneous thoughts are useful in exploring one's mind, as they reflect ongoing experiences and value systems. In the present study, we investigated how the spontaneous thought contents are associated with happiness. To capture individuals’ thoughts, we utilized a Free Association Semantic Task (FAST) where participants (n = 210) generated chains of concepts starting from given seed words. The self-generated concepts were analyzed with a natural language processing (NLP) approach where each concept was represented by a vector of 300 semantic features. Based on the extensive literature supporting the significance of social relationships for happiness, we tested whether happy individuals think more about friends. Participants with higher subjective well-being, in particular those with more frequent positive affect, generated concepts semantically more similar to 'friend,' and showed a trend of aligning their thoughts with 'friend' over time. Interestingly, the semantic associations with 'money' were not linked to subjective well-being. These results were replicated and generalized in an independent sample (n = 350). Furthermore, in a dilemma task where participants had to indicate the degree of income increase that would make them willing to accept a lucrative job offer at the cost of sacrificing their close relationships, the prevalence of friend-related concepts among happier participants predicted their tendency to value close relationships over monetary gains. By construing individuals’ minds with a novel computational approach, our work elucidates how the value of social relationships is manifested in spontaneous thought contents and everyday decisions, which may consequently contribute to happiness.