Formal operations and field independence in a heterogeneous sample

25 sixth grade students from diverse socioeconomic backgrounds were administered two Piagetian formal operational tasks (bending rods and balance beam) and a test of field independence. A Pearson product-moment correlation coefficient of .92 (p less than .001) was found between the two formal operational tasks. Correlation between the formal operational tasks and field independence were .81 and .77 (p less than .001) respectively. These values support the hypothesis of a unified stage of formal reasoning and also support the hypothesis that a degree of field independence is required for the development of formal stage reasoning.