There was no difference in the mean IQ for boys and girls. The mean age at which the children could sight read was before age 4. The child who tests above 130 IQ is typically large and strong for his or her age, healthier than average and contributes far less than his quota to juvenile misbehavior. Perhaps the stereotype about gifted children being smaller than their peers came from the fact that they tend to skip grades. By middle childhood, from 7-12 years of age, gifted children tended to be 2.5 centimeters taller than their peers, on average.
Bright children are more likely to be nearsighted.
Children up to about 140 IQ tolerate the ordinary school routine quite well, achieving excellent marks without serious effort. But above this status, children become increasingly bored. Children at or above 180 IQ are likely to regard school with indifference or positive distaste, for they find nothing interesting to do there. Gifted girls are far less interested in traditional girls' play than unselected girls are. Children who test very high tend strongly to work out forms of solitary, intellectual play.