An Experimental Study of the Development of Formal Operational Thought

KUHN, DEANNA, and ANGELEV, JOHN. An Experimental Study of the Development of Formal Operational Thought. CHILD DEVELOPMENT, 1976, 47, 697-706. Fourth and fifth graders took part in a 15-week intervention program during which they confronted problems requiring formal operational thought. Subjects showed advancement toward formal operations on the pendulum and chemicals problems (Inhelder & Piaget 1958) and on a third problem designed by the authors on both immediate and 4-month posttests. Density of exposure to the problems (once per 2 weeks, once per week, twice per week) was monotonically related to amount of advancement. An additional group of subjects who were also given explicit demonstrations of formal operational solutions to the problems showed no more advancement than subjects given exposure alone. Results were interpreted in the context of Piaget's equilibration theory (1971). Implications for Inhelder and Piaget's (1958) theory of formal operations are discussed.