Key points are not available for this paper at this time.
The quotation is from chapter 1 of this rather uneven symposium volume, and was written by Julian C. Stanley, professor of psychology at Johns Hopkins University and director of the study of mathematical precocity which is the subject of this book. With chapters by several of his associates in the study, and two chapters of more independent commentary, the text adds up to a defense of the quoted proposition, and a certain amount of evidence concerning Prof Stanley's proposed cure for what is a disease afflicting roughly 10,000 American youngsters in the age group studied. Out of 450 self-selected contestants in a Baltimore County mathematics competition in 1972, the 35 topscorers on the SAT mathematics test
Stanley et al. (1975) studied this question.