Both points you make are massively incorrect. Humans do have massive genetic diversity, in physical characteristics as well as mental ones). In the last decade

Both points you make are massively incorrect. Humans do have massive genetic diversity, in physical characteristics as well as mental ones). In the last decade, GWAS analysis has now lead to the ability to identify the gene combinations responsible for intelligence (as well as height, various cancer predispositions etc), and predictive ability is high (i.e. predicting cohort differences in income, years of education etc just from genetic material). It is also something both extremely useful and important to think about both how to avoid both nature and nurture components of intelligence. Preventing diseases detrimental to brain development (like using unleaded fuel and paints) are some of the best bang for the buck on a population level, and maximizing the genetic potential of your offspring by avoiding genetic faults and choosing positive traits while doing IVF will be an unavoidable consequence of current research.