Age differences in voluntary association memberships: fact or artifact.

OBJECTIVES To determine if the curvilinear relationship between age and voluntary association memberships is due to compositional differences between age groups. METHODS Data are drawn from 12 nationally representative surveys covering the period 1974-1994 and including items on membership in 16 types of associations. Age is categorized into 14 groups ranging from 18-24 through 85+. Patterns of age differences in number of association memberships are examined before and after controlling for several variables related both to age and to memberships. RESULTS At the bivariate level, number of memberships increases through ages 40-44 and then declines fairly steadily. When controls for compositional differences are introduced, the curvilinear pattern of age differences is replaced by one showing an increasing number of memberships through ages 55-59, a slight decrease in the 60-64 age group, and then generally stable membership levels through the 85+ age group. DISCUSSION The lower levels of voluntary association memberships of older persons consistently identified in bivariate analyses appear to be largely due to differences in compositional characteristics between the older and other age groups.