Did a little poking around the 3uD question. Interesting result. Experimental Psychology + Chess + UK =

Does Chess Need Intelligence? – A Study with Young Chess Players

Merim Bilalić

Department of Experimental Psychology

Oxford University

South Parks Road

OX1 3UD Oxford, Great Britain

https://www.researchgate.net/publication/222434978_Does_chess_need_intelligence_-_A_study_with_young_chess_players