Loneliness as a double-edged sword: an adaptive function with maladaptive consequences

Loneliness is a construct that has increasingly been studied over the last decades. Although many people experience loneliness at some point in their lives without severe consequences, a vast body of empirical work has shown the detrimental effects of loneliness, suggesting that loneliness affects psychological well-being (e.g., depression, anxiety, lower self-esteem) as well as physical health (e.g., cardiovascular disease), and even early mortality. Recent theoretical work has suggested that the duration of loneliness might explain why loneliness might be beneficial for some people but destructive for others. Specifically, short-term loneliness might result in increased attempts to regain social connection and therefore serve an adaptive function, whereas long-term loneliness might result in maladaptive health outcomes. With this review, we highlight the double-edged sword of loneliness–that is, its adaptive function versus its maladaptive consequences–and we summarize the different ways in which previous work attempted to explain this phenomenon. Moreover, we aim to pinpoint some inconsistencies in the conceptualization and measurement of the duration of loneliness in previous work, and we offer considerations for future research to move the field forward.