Great response, concede to most of your points except... if you want a practical example give a girl a street directory and ask her to navigate. If she turns the map chide her, if she's unable to determine left from right without turning the map she has limited spatial skills.
To compare we could easily gather a sample of men and women and test this, with maps, and those questions which show shapes rotated and ask you to identify which one doesn't match etc...
Then there's the fact most of this research has been done with an MRI, not by simple dissection.
However I appreciate you're unwilling to take a hard stance on a complicated, and controversial topic...
Also your suggested criterion are not specific enough... games is a huge range of things... are we talking about chess or word association?
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