Three groups (students, nonprofessionals, and professionals) of 24 subjects differing in age and education completed a 60-item spiral omnibus test and two criterion measures (Intellectual Efficiency scale and Life Attitude Profile). Half of the omnibus questions (based on general information, social judgement, and numerical ability) had been judged as tapping knowledge unrestricted to students or middle-aged adults not in school, and the other half were drawn from standardized intelligence tests. The three groups performed equally well on the new items but, on the conventional ones, the nonprofessionals obtained lower scores than the students or professionals. However, a multiple regression analysis showed that, although none of the items predicted Life Attitude Profile scores for any group, both types predicted intellectual efficiency scores for professionals and, contrary to expectation, conventional and unbiased ones predicted intellectual efficiency for nonprofessionals and students, respectively.