International Review of Industrial and Organizational Psychology

ETHNIC GROUP DIFFERENCES AND MEASURING COGNITIVE ABILITY 219of items completed, and the number of items completed accurately, mayincrease for all groups. Thus, the increased time available to test-takersoften exacerbates the extent of group differences.Some contradictory findings may relate to the differential speedednessof the tests studied and ceiling effects in scores before the experimentalmanipulation.Test DesignMany critics suggest that differences in performance between groups is aresult of tests that reflect the reasoning processes, definitions of intelligence,cultural assumptions, linguistic patterns, and other features of the testwriters.In the USA, and to a large extent around the world, this is thedominant White culture, influenced as it is by rationalism, Western Europeancultures, and Judeo-Christian thought. In this section we review someof the mechanisms suggested and studies that attempt to check whether thesedo affect group differences. Helms (1992) is perhaps one of the more coherentcritics and, while researchers have begun to address some of the hypothesesshe raises, there are still only a few relevant studies. Many of these areperformed in a research context and investigate trends in small samples ofcollege students. Larger studies with more realistic occupational groupswould be desirable.Standardization on White groupsHarrington (1988) pointed out that typically tests are standardized usingpredominantly White samples. It could be that this process is tending toselect items and create tests that favour the White group. One study thatexamines this is by Hickman and Reynolds (1986), who tested this hypothesisby creating two forms of a cognitive battery for children standardized onmajority Black and majority White samples, respectively. They found nodifference in score patterns for the two forms. Similar null results werefound by Fan, Willson, and Kapes (1996). Jones and Raju (2000) domanage to find some effects with an Item Response Theory (IRT)-basedapproach—their results are discussed in the next section.Differential item functioningIf there are cultural factors that make tests and items differentially difficultfor some groups, it is likely that these load more on some items than onothers. Attempts to identify inappropriate items through reviews were notalways successful. A Wechsler Intelligence Scale for Children (WISC) itemidentified as unfair to Black children turned out to be relatively easier forthem. ‘Culture fair’ tests, such as the Cattell Culture Fair Intelligence Test