_Mother_. A's mother was graduated from high school at the age of 18 years. Before marriage she was in business, as an executive in charge of advertising for one of the largest drug concerns in this country. She has handled business affairs involving large sums for a tobacco company. She also did some newspaper work. Formerly she had excellent health, but she has not been entirely well since the birth of her children. She was 27 years old when A was born. _Noteworthy relatives_. In the paternal branch these include cousins who founded the Banking House of Tuch, in London. The father's maternal grandfather (A's great-grandfather), a tailor, devised and patented a union suit, said to have been the first union suit. He also invented an improved buckle for adjusting men's vests in the back. It was said of him, "He was always trying to invent things." Noteworthy relatives of the mother include the founder of the Lemaire Optical Goods firm. This firm has an international reputation for fine lenses. A cousin of the mother is a judge. Another relative was a leader of Jewish reform movements. _Immediate family_. A is the first-born child. He has one brother, three years younger than himself. This brother is large, strong, and handsome. His IQ on repeated tests, at intervals of a year, has stood at 145, 152, 145, 161. He too displays the special interest in mathematics which characterizes A. For instance, at the age of 5 years he set himself the project of counting all his footsteps until he had counted a million consecutive steps. This project he carried out, his parents submitting to the numerous inconveniences incident to it. The growth of this brother affords an interesting comparison with that of A, since we have here two children, both of extremely superior intelligence, of the same ancestry, and living under the same school and home conditions, one of whom is nevertheless as superior to the other--in terms of IQ--as that other is superior to the average child. PRESCHOOL HISTORY