>> If I had to guess, I would say genetics. I mean, its a game about spatial patterns.
What do "spatial patterns" have to do with genetics, in this context?
Anyway, judging from your comment you probably haven't heard of Judit Polgár:
Judit Polgár (born 23 July 1976) is a Hungarian chess grandmaster. She is generally considered the strongest female chess player of all time.[1] In 1991, Polgár achieved the title of Grandmaster at the age of 15 years and 4 months, at the time the youngest to have done so, breaking the record previously held by former World Champion Bobby Fischer.
Polgár was born on 23 July 1976 in Budapest, to a Hungarian Jewish family.[10] Polgár and her two older sisters, Grandmaster Susan and International Master Sofia, were part of an educational experiment carried out by their father László Polgár, in an attempt to prove that children could make exceptional achievements if trained in a specialist subject from a very early age.[11] "Geniuses are made, not born," was László's thesis. He and his wife Klára educated their three daughters at home, with chess as the specialist subject.[12] László also taught his three daughters the international language Esperanto. They received resistance from Hungarian authorities as home-schooling was not a "socialist" approach. They also received criticism at the time from some western commentators for depriving the sisters of a normal childhood.
Traditionally, chess had been a male-dominated activity, and women were often seen as weaker players, thus advancing the idea of a Women's World Champion.[13] However, from the beginning, László was against the idea that his daughters had to participate in female-only events. "Women are able to achieve results similar, in fields of intellectual activities, to that of men," he wrote. "Chess is a form of intellectual activity, so this applies to chess. Accordingly, we reject any kind of discrimination in this respect."[14] This put the Polgárs in conflict with the Hungarian Chess Federation of the day, whose policy was for women to play in women-only tournaments. Polgár's older sister, Susan, first fought the bureaucracy by playing in men's tournaments and refusing to play in women's tournaments. Susan Polgár, when she was a 15-year-old International Master, said in 1985 that it was due to this conflict that she had not been awarded the Grandmaster title despite having made the norm eleven times.[15]
https://en.wikipedia.org/wiki/Judit_Polg%C3%A1r
So, of three women that were purposefully trained from an early age to play chess, two became grandmasters and the other an International Master. Either genetics has nothing to do with it, or the Polgárs are a very special family, genetically speaking. Which is the most likely?