Overlapping attendance categories can manufacture the curvilinear relationship by labeling.

Evidence

Do you see that the criterion for the Moderates overlaps that of both the Lows and the Highs? In particular, the frequent category of people who say they go to church once a week could be called “Moderate” in one study and “High” in another. Since the Moderates play a critical role in establishing a curvilinear relationship, this very permeable membrane surrounding their definition makes me squirm in my chair. So I cannot agree it has been shown that very active church members are as unprejudiced as nonmembers, or that the curvilinear relationship has been demonstrated among church members. — Bob Altemeyer, The Authoritarian Specter, 1990

Categorization

• DEFINE: Illustrates how fuzzy category boundaries in measurement can fabricate the statistical shape of a relationship.
• SEED: Essay angle: how ‘permeable membranes’ around category definitions let researchers manufacture the curvilinear/v-shaped results they expect across many fields.