That the yes-no gesture contrast is probably infantile and not culturally implanted later on is supported by the fact that children who are born deaf and blind fall naturally into the pattern without modelling.

• 这种肯定否定相对照的动作可能是本能的，而不是从后天文化中移植的，这一点有事实为证：生来又聋又瞎的婴儿勿需模仿，自然而然就会做这个动作。