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Lester W. Sontag, Charles T. Baker, Virginia L. Nelson, Mental Growth and Personality Development: A Longitudinal Study, Monographs of the Society for Research in Child Development, Vol. 23, No. 2, Mental Growth and Personality Development: A Longitudinal Study (1958), pp. 1-3+5+7+9+11+13-55+57-81+83-85+87+89-139+141-143
Sontag et al. (Wed,) studied this question.