The Influence of Group Competence on Individual Willingness to Join.

In everyday life, individuals frequently encounter situations in which they may join new groups; however, previous research has primarily focused on issues that arise after group formation, leaving insufficient attention to the processes preceding spontaneous group affiliation. This study investigates how different levels of group competence influence individuals' willingness to join, using Optimal Distinctiveness Theory as its theoretical framework. Through two experiments, it systematically examines participants' willingness to join groups of varying competence levels and how this willingness is moderated by participants' own competence. The results indicate that high-competence groups demonstrate stronger member attractiveness and effectively promote individuals' willingness to join. Crucially, the group's attraction to individuals is moderated by individuals' own competence. When group competence is lower than one's own competence level, willingness to join increases as group competence rises toward one's own level. Strikingly, when group competence exceeds one's own, willingness to join remains uniformly high and stable, rather than decreasing as Optimal Distinctiveness Theory would predict. These findings suggest that individuals engage in a psychological trade-off based on competence alignment when autonomously choosing whether to join social or professional groups. We interpret this pattern as evidence for a "downward aversion, upward assimilation" heuristic in group affiliation decisions. The present research also has implications for understanding how groups can strategically manage their reputation to attract prospective members, as well as how individuals make group-joining decisions at different stages of career development.