This investigation analyzed sex-related and age-related differences on spatial visualization tasks, reasoning tasks, and mathematical problem-solving tasks; and the effects instruction in visual thinking would have on these differences. Students in fifth grade, ninth grade, and in college, were tested before and after twelve weeks of instruction…

Performance of 162 children, ages five to seven, on concept formation and perception tests indicated that enforced delay in responding minimally affected all reflective subjects and impulsive boys; impulsive girls improved. (Available in microfiche from: Carfax Publishing Company, Haddon House, Dorchester-on-Thames, Oxford 0X9 8JZ, England.) (CP)