左撇子的起源也许和人类的起源一样久远。左撇子和右撇子，是一个问题的两个方面，可能我们先应该回答的是，人类为什么发展成许多活动偏重于用某一侧肢体呢？ 有人从人类的能量体系角度解释人类活动集中于某一侧肢体的原因。集中使用一侧手，主要训练单只手比训练两只 Lefty’s origin may be as old as human origin. Left-handedness and right-handedness are two aspects of a problem. Perhaps the first thing we should answer is why do humans develop so many activities that they prefer to use one limb? Some people explain the reason why human activities are concentrated on one side of the limb from the perspective of human energy systems. Focus on using one hand, mainly training one hand versus training two