Answers are grounded in this paper and cite their sources.
(1950). Institute of Child Welfare, University of Minnesota, Minneapolis 14, Minnesota. The Journal of Psychology: Vol. 30, No. 1, pp. 199-227.
No takes yet. Share an insight, caveat, or question.
Merrill Roff (1950) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: