Tight spaces, hard races: Development and testing of a crowdedness scale linking crowded environments to competition.

Crowdedness is defined as the subjective sense of spatial and social constraint caused by limited personal space and the presence of others.Although subjective crowdedness is distinct from objective population density, it is often operationalized using density measures, which undermines construct validity.Although evolutionary life history perspectives have assumed that subjective crowdedness serves as a socioecological cue of competition, this link has yet to be directly tested and thus remains largely hypothetical.Across four online studies involving 1,760 U.S. adults, we developed and validated an eight-item Crowdedness scale capturing perceived and experienced crowdedness and examined the link between subjective crowdedness and perceived competition.It was found that subjective crowdedness is distinct from objective residential population density.In addition, subjective crowdedness robustly predicted perceived competition, above and beyond objective residential population density.These findings provide direct evidence that subjective crowdedness independently cues competition.Our research offers a theory-consistent measure that equips researchers with a tool to investigate the psychological consequences of crowded living. Public Significance StatementThis research develops and validates an eight-item Crowdedness scale that captures people's subjective sense of crowding.The findings show that feelings of crowdedness, more than how densely populated an area actually is, reliably predict whether people perceive their everyday environment as competitive.The new Crowdedness scale offers a theory-consistent tool for examining how crowded living conditions shape competitive climates and related psychological outcomes.