Here is the first thing I can find: http://www.news-medical.net/news/2005/04/26/9530.aspx There is a picture of the IQ curves for various races somewhere, I can't find it right now though. It isn't the same picture for every race. I am not sure exactly which facts you question though? Genetic components have been well established for various mental illnesses, disease susceptibilities etc. Of course over time new combinations of genes are expressed in humans as people mate and reproduce, and even random mutations happen and sometimes they even have beneficial effects. I am not sure exactly what you mean by conditioning, it is simply evolution.