Mkuu Nguli kuna some proof
Regression towards the mean heritability of IQ

Any large enough group of IQ scores can be modeled using the
Gaussian distribution, with a
mean score of 100.
The heritability of IQ measures the extent to which the IQ of a child is measurably influenced by the IQ of its parents. As IQ is a quantifiable phenotype, one can estimate the expected IQ of child using the equation
, where
- is the expected IQ of the child,
- is the mean IQ of the population to which the parents belong,
- h2 is the heritability of IQ,
- m and f are the IQs of the mother and father, respectively.[60]
The equation asserts that, on average, the IQ of a child tends to the mean IQ of the population. For instance, if the heritability of IQ is 50% and the mean IQ of a population is 100, then a couple with an average IQ of 120 will, on average, have a child with an IQ of 110. Similarly, a couple with an average IQ of 80 will, on average, have a child with an IQ of 90.
Source :
http://en.wikipedia.org/wiki/Heritability_of_IQ