Even if every child entered the world with equal innate ability,
by the time they were grown they would nevertheless have very
different mental capabilities. Innate ability is the ability
that exists at the moment of conception, but nobody applies for
a job or for college admission at the moment of conception. Even
between conception and birth, other influences affect the
development of the brain, as well as the rest of the body. The
mother's diet and her intake of alcohol or drugs affects the
unborn child. Differences in the amount of nutrition received in
the womb create differences even between identical twins. Where
one of these identical twins is born significantly heavier than
the other, and the lighter one falls below some critical weight,
the heavier one tends to have a higher IQ in later years. They
may be the same weight when they become adults, but they didn't
get the same nutrition back when their brains were first
developing. Inequalities have so many sources that this fact
undermines the simple