This study examined the relationship of tutorial enrichment of cognitive processes and reinforcement of lengthened response latency to measurements of impulsivity in 3- and 4-year-old children in a typical preschool setting. In a pretest-posttest control group design, 48 impulsive subjects (24 male and 24 female) were randomly assigned to tutorial and nontutorial groups, producing eight cells with six observations per cell. Subjects were administered the Kansas Reflection Impulsivity Scale for Preschoolers (KRISP), Form A, and the Slosson Intellingence Test. Tutorial subjects then received tutoring with standard curriculum materials in two sessions per week for a 6-week period. During tutorials, subjects were provided with at least two opportunities for reinforcement per minute for lengthened response latency and systematic search strategies. At the same time nontutorial subjects continued their usual preschool routine. After 6 weeks, all subjects were administered the KRISP, Form B. The findings indicated that impulsivity was modifiable through the tutorial process, although the process was more effective for the 3-year-olds than for the 4-year-olds. The belief in orthogonality of efficiency and impulsivity was corroborated, as were the stability and independence of the impulsivity trait. (JMB)