I noticed improvement on speed of my thinking, mathematlcal and logical skills, including using logic in debates, even philosophy, but that only because I already was interested and had some skill in those areas before studying chess.
Decision making and problem facing abilities, also increase.
I became more logical and analytical (although I already was like that before).
But all of that is result of STUDYING chess, not playing.
Playing blitz will give you a little endorphin when you win and make you upset when you lose, not much more.
I saw great improvements in my I Q immediately after taking up chest 25 years ago - - when I first started I could not spell chest and then after playing chest for a year I could finally spell chest - - - the hardest thing for me was learning how the horsey moved - - - - - so with in a year after taking up chest my I Q increased 100 points - - if I were high commander of north america - - I would get rid of the entire school curriculum and totally replace it with chest books chest courses and chest instruction - - then the students would study chest forever and would not graduate until they could and would beat a chest grand master - -
- - - a faster way to become smarter believe it or not - - is to simply buy a pair of fake glasses - - when I wear my reading glasses or my fake glasses people tell me - - my I Q doubles - - from 50 to 100 - - - or so they tell me