Reported is a study to determine the role of the affective measures of need to achieve (nAch) and risk taking in determining the acceleration or retardation of cognitive development as defined by Piaget. Students in the fourth and sixth grades of two schools differing according to socioeconomic status (SES) were the subjects for this investigation. Sixteen were selected from each grade. SES was determined on the basis of local real estate values and according to Hollingshead's Index of Social Position. Each subject was privately interviewed twice. The Aronson Non-Verbal Expressive Behavior Measure for the determination of need to achieve (nAch), and three risk tasks were administered during the first interview. During the second interview, two weeks later, four Piaget-type concrete operational tasks were administered. Analysis of the data for nAch indicated that this factor was relatively stable in the sample population. No significant differences were noted between SES levels for each grade or between grade levels. No statistical differences in risk level were noted except one, which indicated that high SES, high nAch sixth-grade subjects took a greater number of moderate risk chances on one task--a rink-toss game (p less than .05). Some major conclusions drawn included: (1) the personality factor nAch was well established in fourth-grade students; (2) there was little or no change in nAch, with age, beyond the fourth grade; and (3) risk preference may be allied with nAch, but not necessarily to SES or grade level. (Author/EB)