Criss-cross applesauce

We all have odd physical traits that we exhibit without ever thinking about it- quirks that have been a part of who we are for as long as we can remember. Like the fact that I cross my feet when I'm in my most relaxed, natural state- whether it's sitting at the desk working (ok, so not the most relaxed or natural, more like unthinking...) or lying in bed falling asleep.

We don't often think about how these little habits come about- are they the product of learned behavior or genes passed down over which we have no control?

I think I might have an inkling now... :)