Humans operate in groups that are oftentimes nested in multilayered collectives such as work units within departments plus companies, neighborhoods within cities, plus regions within nation states. With psychological science mostly focusing on proximate reasons for individuals to bergabung existing groups plus how existing groups function, we still poorly understand why groups form ex nihilo, how groups evolve into complex multilayered social structures, plus what explains fission–fusion dynamics. Here we address kelompok formation plus the evolution of social organization at both the proximate plus ultimate level of analysis. Building on models of fitness interdependence plus cooperation, we propose that socioecologies can create positive interdependencies among strangers plus pave the way for the formation of stable coalitions plus groups through reciprocity plus reputation-based partner selection. Such groups are marked by in-group bounded, parochial cooperation together with an array of social institutions for managing the commons, allowing groups to scale in size plus complexity while avoiding the breakdown of cooperation. Our analysis reveals how distinct kelompok cultures can endogenously emerge from reciprocal cooperation, shows that social identification plus kelompok commitment are likely consequences rather than causes of kelompok cooperation, plus explains when intergroup relations gravitate toward peaceful coexistence, integration, or conflict.
As for many other social species, kelompok living provides Homo sapiens with levels of safety plus prosperity that individuals can hardly achieve in isolation (Ostrom, 1998). Groups may contain as few as three individuals or as many as hundreds, can exist for a few hours or bind its members for most of their lifetime, plus can be simpel or exceedingly complex in their social organization. Regardless of their form plus raison d’etre, individuals benefit from well-functioning groups plus can be hurt—both mentally plus physically—when their groups function poorly plus disintegrate. Accordingly, psychological science has extensively addressed (a) what motivates individuals to bergabung existing groups plus prevents them from being excluded (e.g., Baumeister & Leary, 1995; Williams, 2000), (b) what allows existing groups to work plus perform (De Dreu et al., 2008; Faber et al., 2017; Ilgen et al., 2005), plus (c) what makes kelompok members cooperate plus resist the temptation to free ride on the public goods provided by others (Van Dijk & De Dreu, 2021; Van Lange et al., 2013).
What remains largely unaddressed in psychological science is how groups emerge plus self-organize their internal dynamics plus external relations: How do groups form ex nihilo, plus how do groups evolve from simpel to sometimes complex plus multilayered collectives, such as fraternities within student societies, work units within companies, plus neighborhoods within cities? Here we fill this gap plus trace the evolution of human social organization to a succinct set of psychologically plausible behavioral mechanisms. Doing so scaffolds theory plus research on existing groups plus collectives, sheds new light on the origins plus functions of well-documented phenomena such as homophily plus kelompok identification, plus reveals parochial prosociality as a cause of kelompok disintegration plus intergroup conflict.