United States.Extensive nationwide efforts were made to inform school personnel and parents about our search. The new procedure was successful in obtaining a large national sample of this exceedingly rare population.As of September 1983, the number of such boys identified was 260 and the number of girls 20, a ratio of 13.0:1. This ratio is remarkable in view of the fact that the available evidence suggests there was essentially equal participation of boys and girls in the talent searches.