Abstract: 51 children from the same three age groups of 2 1/2—3 years, 3 1/2—4 1/2 years and 5—6 years as in a former study were examined after an interval of one year to observe if they did follow the trend of the 3-stage development as suggested. The results fully confirmed our former conclusions. That repitition did not make children adopt the methods of their respective old solutions but with a tendency for the solution appropriate to a more advanced stage argues for the role of exercise in mental development.

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