Why would anyone ever even suspect otherwise? I've been telling people this for decades. It makes ZERO SENSE that chess would make you smarter. Chess is no more an intellectual activity than carefully watching a football match.
People don't understand how you can manipulate and fix studies like this to show what you want. All of the other studies were done with a mind to "prove" that chess makes you smarter. They run the same scam with those "brain training" software farces and other "studies".
No doubt there'll be guys feeling offended at this and looking through it and coming out with some ridiculous excuse as to why it doesn't count.
https://core.ac.uk/download/files/14/333373.pdf
and I've not been partial, not that they care
Go ahead, we are impartially awaiting