The study analyzes the nature of the relations between participation in, and joining, voluntary associations and seven independent variables measuring dimensions of occupational tasks, organizational structure, and attitudinal importance of contacts. The three dependent variables, i.e., participation, joining one or more associations, and joining three or more associations vary, to some degree, independently of one another and, therefore, are treated separately. The seven independent variables are mental-manual, colleague control, bureaucratic control, formal contacts unimportant, informal contacts unimportant, leadership, and isolation. Twelve occupational groups were assigned numerical percentage scores on each of the independent and dependent variables. Correlational and multivariate analysis was performed on the variables. Task generalization as an explanation of participation and joining receives strong support from the study. Overall, three task-based variables, leadership, bureaucratic control, and mental-manual, explained most of the variation in the dependent variables. In general, more of the variation is accounted for in participation and joining three or more associations than in joining one or more.