The relative difficulty levels of Stanford-Binet items between the ages of four and six among prekindergarten Head Start children were studied. A comparison sample of prekindergarten white middle class children was included to evaluate the age norms on a culturally typical sample of children and to assess performance on the Binet as it might relate to cultural differences. The analyses required that the items be arranged in order of difficulty and then examined for the degree to which the reordered items appear in their assigned age groups. Similar analyses were conducted for all groups to determine variables due to sex and race differences. Results suggest that the age progression properties of the items are relatively consistent between lower and middle-class children, between males and females of either SES, and between races among lower class children; however, the age-placements of many items on the 1960 revision appear inappropriate, although the negative influence of such items is distributed evenly over SES, race and sex. Examples of item misplacement are discussed. (Author/LR)