Lonely and self-centered? A meta-analysis of the link between prosociality and loneliness.

Abstract

The Evolutionary Theory of Loneliness (ETL) posits that loneliness may motivate individuals to approach others, but at the same time increase focus on self-preservation and safety, resulting in egocentric behavior, negative social expectations, decreased trust or increased social threat monitoring. Since the empirical evidence for the link between loneliness and prosociality is far from conclusive, the current meta-analysis aims to estimate the strength of this relationship and explore factors impacting it. To identify peer-reviewed papers reporting original quantitative data regarding link between loneliness and prosociality, three databases (PsycINFO, PubMed, Scopus) were searched on June 2nd, 2023. Separate random effects models were created for the main meta-analysis and secondary analyses testing the moderating role of age and gender using meta regression and subgroup analyses to assess the differences in cultural background, type of prosociality measure (declarative, behavioral, informant-ratings) and form of prosocial behavior (e.g. altruistic, anonymous). The final sample included 35 studies involving 44 764 participants (53.56% women, Mage = 24.93). Our meta-analysis indicated significant, albeit weak effect size for the negative correlation between loneliness and prosociality (r = -0.12, 95% CI from -0.19 to -0.05), which was stable among agents’ sociodemographic characteristics, but differed significantly between types and forms of prosociality. These findings support the existence of a link between prosociality and loneliness, which can be generalized across age, gender and culture, while emphasizing the need to further study its potential moderators. Importantly, a scarcity of behavioral and neural data among the adult samples was observed.