I think Satoshi is an individual person. He writes with a consistent style. I doubt he's American, since he sometimes uses British spelling.
This thread is old. Since 2011 it has been created. But what interest me to respond to this that this response of theymos explanation through contemplation that it assume that he doubt that Satoshi is from American, with this. It's shows that theymos have not seen Satoshi in person, but i assumed that theymos communicate wiy Satoshi even seat man to man and talk, that means no body will know if Satoshi is man or woman. This world is very big world.