This chapter explores the phenomenon of social essentialism along five conceptual dimensions. Firstly, it investigates the natural domain of living kinds, which serves as a prototype of essentialist thinking. The natural domain lets us observe continuity of living kind exemplars throughout life spans and across generations, along with other classic characteristics of essentialist thinking. Social essentialism primarily manifests in groups where membership is determined by birth, such as ethnic groups, which develop a strong sense of identity and ethnic marking. Subsequently, I present two theoretical approaches to the origins of essentialist cognition. The first approach posits that essentialist cognition is an innate cognitive feature, while the second suggests that it is an enculturated way of thinking within the cultural niche. Both approaches postulate an evolutionary selection pressure: the former on individuals and the latter on the institution of enculturation. The case of aristocracy is discussed as an example of identity formation in ‘ontogenetic niches.’ The final section examines the role of instrumental essentialism, which serves political purposes of social groups. In political contexts, hence, essentialist notions can be seen as a tool that can be used for socially positive or negative goals.