Fair enough, let me try again:
https://chess.stackexchange.com/a/24946
> The most comprehensive and recent publication I've found related to this question is The relationship between cognitive ability and chess skill: A comprehensive meta-analysis.
> The bottom line is that according to a meta-analysis of numerous studies, there is clearly a correlation between chess skill and cognitive ability, but cognitive ability explains only about 6% of the variance in chess skill (12% if you only consider numerical ability only). There must be other factors as well (e.g., training), some of which could be more important than cognitive ability.
From my personal observations I very much agree with 6%.