Over time I have noticed a lot of tall, skinny guys that cross their legs that were probably of high intelligence but also extremely weird. Like borderline autism weird, or in one case, pre-schizophrenic weird.
Just some very unscientific observation on my part.
Edit: In terms of the article you posted, the crossing I describe fits with the contractive pose. Legs crossed narrowly, almost intertwined with shoulders hunched forward.
The way the guy sits in the statue in the picture you posted loks kind of relaxed and confident to me. Expansive in terms of the article in the way that his hand is draped across the back of the bench.