Saltys correct, but genetic memory helps for sure and its origanal base. You will notice that sea level Blacks living in tropical climates are genetically good sprinters, Kenyans living at over 3,ooo metres are good at endurance events. But with the help of science and hard work you can achieve good results. As far as Boxing I believe its down to knowing what you are doing Biomechanically Bit Part Whole, more so than reflex as Ive noticed in the field coaching. Theres a field of thought of return Technique which Im a believer is the way forward incorperating Isometic Stretching.