>genetics determine nothing
Genetics determines almost everything at the population level. All the stats people use to disprove heritable are done on children who are still growing. Children are influx and correlate poorly with their parents. Once they stop growing everything correlates extremely highly. Environment can cause stunts of growth with malnutrition. This will effect height and IQ. This mainly applies to very poor 3rd world countries. Once you hit a fairly low baseline of nutrition height and IQ gains stop. The BETTER OFF a country is, the CLEARLY genetics become, because these low baseline factors have been eliminated.