Abstract: Fisrt grade children (mean age= 6 years 7 months) were classifiedinto reflective (n=33) and impulsive(n=31) by Matching Familiar FigureTest. They were also tested on logical reasoning tasks in three periods:pretest, training and posttest. Analysis of children's spontaneous tenda-ncy of self-explanation suggests that: 1)The reflective children paid muchattention to the sureness of their judgments during all the three periodsof testing; 2)The impulsive children were eager to respond quickly at thepretest, but during the training, owing to the explanation of the experi-menter, they changed their reflectiveless habit and focused on the surenessof their answers, at the posttest however, they resumed their quickresponding tendancy. At the pretest both groups did equally poorlybecause the tasks proved to be too difficult, during the training both didequally well,and at the posttest the impulsive children regressed while thereflective children did not. The educational implications of the findingsare discussed in this paper.

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