PurposeThe purpose of this study was to investigate organizational and occupational homogeneity, compare homogeneity at different levels of composition, and uncover a mechanism for homogeneity.Design/Methodology/ApproachData were obtained from an archival data base of current employees (N = 23,933) in 40 organizations, 19 major job groupings, 42 minor job groupings, and 115 detailed job titles.FindingsSupport for homogeneity within organizations and occupations was found, regardless of the granularity with which occupation were defined. Homogeneity estimates were smaller than prior estimates in the literature based on smaller, less diverse samples. Occupational homogeneity was significantly greater than homogeneity at the organizational level for neuroticism and extraversion. As a potential mechanism, we demonstrated that occupational interest could predict personality at the occupational level.ImplicationsInvestigating homogeneity effects with a large, representative sample and simultaneously considering occupation and organization helps to advance our theoretical understanding of the Attraction–Selection–Attrition process. This study provides evidence of relative homogeneity effects and mechanisms. Such knowledge could help inform the selection, training, and socialization tactics employed by practitioners.Originality/ValueLittle is currently known about how within-occupation homogeneity in personality relates to within-organization homogeneity, or the influence of vocational interests on such homogeneity. We provide a methodological update to decompose and compare organizational and occupational influence on personality homogeneity. We also assess homogeneity at three levels of occupational granularity, and delineate a mechanism for personality to become homogeneous at the occupation level. |