While I think people underestimate how much hard work can overcome low cognitive talent, such that probably a lot of people with average iq can hit a chess rating of 2,000 if that was their primary goal in life, I also think Hikaru's IQ probably isn't actually only 102. Online tests aren't so rigorous. Just from hearing him talk he seems to have the usual nuanced understanding of the universe on a variety of domains that would not be typical of an average iq. he also took the chest while streaming and talking to chat