The influence of environmental factors on cognitive ability plays a role only in childhood and adolescence, and among adults their influence drops to almost zero and only genetics counts. Of course, in childhood, only genetics also counts. Note: remember that whites incorrectly include Arabians having negroid genes (10%), Sicilians having up to 6% negroid genes, Indians having up to 6% Denisovan genes. This is the sole reason why whites in some studies come out dumber than the yellows, which mainly include the Ypoons and Chinese - nations that have been conducting intensive racial purges since time immemorial, so that the share of negroid genes is negligible. In general, a white, pure European, called Aryan by the millennia, is TOP.