Allport’s influential intrinsic-prejudice study used an unpublished questionnaire

Evidence

In an influential study, Allport and Ross (1967) tested the prediction that Intrinsics would be less prejudiced than Extrinsics. Students from Allport’s graduate seminar administered, to 309 churchgoers, measures of intrinsic and extrinsic orientations and several prejudice scales. Foremost among the last was an unpublished Social Problems Questionnaire containing twelve items about blacks, ten statements about Jews, and ten other statements. These prejudice measures were at least somewhat balanced against response sets. — Bob Altemeyer, The Authoritarian Specter, 2001