Six-month-olds don't, and even 12-month-olds don't find anything weird about this, while adults are sophisticated enough to understand that that's an unstable configuration and should fall over.

六个月大的婴儿则不会这么想,即使是十二个月大的婴儿,也没有发现这个木块存在的异常,只有经历世事的成年人才会理解,这不是个稳定的结构,而这个结构是会倒塌的

耶鲁公开课 - 心理学导论课程节选