What about at 2, once they've learnt to walk, amongst many other complex skills? I'm still not getting why wrestling is more innate than any other way of fighting. Flailing limbs is innate. After that, trying to discern between innate and learned behaviour becomes incredibly nebulous. Not just for humans, but any primate and many mammals. I need sources before I'll accept this assertion. And, are we defining the palmar grasp reflex as "wrestling" now?