Imagine that the graph of IQ as a function of parameter p is left-skewed.
Then natural selection is going to produce a population in which values of p are clustered around the optimum with more values slightly below the optimum than slightly above the optimum. In such a population, genes which increase p would paradoxically appear to be associated with both high iq and extremely low iq.
Imagine that the graph of IQ as a function of parameter p is left-skewed.
Then natural selection is going to produce a population in which values of p are clustered around the optimum with more values slightly below the optimum than slightly above the optimum. In such a population, genes which increase p would paradoxically appear to be associated with both high iq and extremely low iq.