It is but how long does it take? I do not believe it is as simple as saying:
Person A has an IQ of 102
Person B has an IQ of 104, therefore; the child will have an IQ of 103. There is no specific IQ gene and so I would imagine that it would take just as long from an evolutionary standpoint to decrease the average IQ as it would for us to loose our tails and stop living in tree's. It certainly wouldn't happen in a matter of 30 years. At least, I don't think it would... I could be wrong but I don't believe I am.
It certainly could happen in 30 years. We could make it happen much faster if we got a genocidal dictator who decided to kill smart people. Pol Pot may qualify.
Birth control is currently the primary natural selection criteria. Anything that can defeat birth control is extremely strongly favored by evolution. Evolution is quite rapid when the selection effects are strong, especially when also starting from a diverse population.
I think you are wrong but I am open to debate if your interested in posting the prerequisite, peer reviewed, case studies on selective breeding for IQ in humans.
I think most of the assumptions I have made a pretty reasonable. We are talking about the evolution of possibly thousands of different genes which could contribute to IQ. This can't be compared to altering the pod size of a pea plant, a rather simple genetic selection, which still takes many generations to take effect.
Person A has an IQ of 102 Person B has an IQ of 104, therefore; the child will have an IQ of 103. There is no specific IQ gene and so I would imagine that it would take just as long from an evolutionary standpoint to decrease the average IQ as it would for us to loose our tails and stop living in tree's. It certainly wouldn't happen in a matter of 30 years. At least, I don't think it would... I could be wrong but I don't believe I am.