Social exclusion refers to being ignored, ostracized, or rejected by others. While social exclusion is a phenomenon widely observable throughout human life, beginning as early as infancy, research into its developmental processes and impacts has only recently begun. Therefore, this paper introduces a representative model and methods used to examine social exclusion, reviews the latest trends in developmental research based on these methods, and discusses future issues and prospects. Specifically, I first introduce Williams’s temporal need-threat model as a key model regarding social exclusion and provide an overview of experimental and non-experimental methodologies applied across participants from infants to adults. Next, I clarify the effects of social exclusion on individuals’ fundamental needs, cognitive, emotional, and behavioral aspects by synthesizing existing findings from adults and developmental studies. Finally, I address theoretical, methodological, cultural, and ethical issues emerging in advancing developmental research and discuss prospects.
