alt Hacker NewsYou're right-handed, right? It is more natural to move your hand in counter-clockwise circles than the opposite. People who have never swirled pasta or anything like that will feel the same if you ask them to make swirling motions with their hands. Inwards is easier - clockwise with your left hand, counterclockwise with your right hand.
A literature search didn't turn much evidence of this at all, let alone conclusive evidence. Any sources? I swirl right hand clockwise. I also draw circles clockwise. One article said circle drawing direction was likely cultural or linked to handwriting systems, not which was more "natural".