[Agrippa]

Large parts of Eurasia were racially progressive - though less gracile - long before the Neolithic revolution and it can't be explained by the Neolithic change. A more gracile bone structure and reduction in temperate zones can be partly explained by effects of the agricultural subsistence patterns, but not the racially progressive tendencies as such, which are much closer related to climate and intraspecific competition.
Its just that those areas with a more favourable climate and stronger intraspecific competition on a higher level were also those which adopted agriculture earlier in most but not all cases.