If we dug deep into the sub-components of Carlsen’s IQ (or perhaps the sub-components of the sub-components), we’d probably find some sub-component where he measured off the charts.
It’s still probably a combination of sub-components + memory (often underrated in IQ discussions) + physical fitness (relevant in long tournaments), not any single one. Quotes on his childhood:
At two years, he could solve 500-piece jigsaw puzzles; at four, he enjoyed assembling Lego sets with instructions intended for children aged 10–14.
Simen Agdestein emphasises Carlsen’s exceptional memory, stating that he was able to recall the locations, populations, flags and capitals of all the countries in the world by age five. Later, he memorised the locations, populations, coats-of-arms and administrative centres of “virtually all” 356 Norwegian municipalities.
Kasparov expressed similar sentiments: “[Carlsen] has the ability to correctly evaluate any position, which only Karpov could boast of before him.
In a 2012 interview, Vladimir Kramnik stated that Carlsen’s “excellent physical shape” was a contributing factor to his success against other top players as it prevents “psychological lapses”, which enables him to maintain a high standard of play over long games and at the end of tournaments, when the energy levels of others have dropped.
Levon Aronian said in 2015: “Magnus’ main secret is his composure and the absence of any soul-searching after mistakes during a game.” (i.e. chess tilt)
Tyler Cowen gave a point of view on Carlsen’s playing style: “Carlsen is demonstrating one of his most feared qualities, namely his ‘nettlesomeness,’… Using computer analysis, you can measure which players do the most to cause their opponents to make mistakes. Carlsen has the highest nettlesomeness score by this metric, because his creative moves pressure the other player and open up a lot of room for mistakes. In contrast, a player such as Kramnik plays a high percentage of very accurate moves, and of course he is very strong, but those moves are in some way calmer and they are less likely to induce mistakes in response.”
It’s still probably a combination of sub-components + memory (often underrated in IQ discussions) + physical fitness (relevant in long tournaments), not any single one. Quotes on his childhood:
and on his distinctive style: