世界知名嘅面部表情研究學者 保羅艾克曼 在巴布亞新幾內亞嘅研究入面 發現好似高山族族人咁 同西方文化完全無接觸 而且有食人習俗嘅部族 聽到一啲令人發笑嘅情景 亦會顯露笑容
In his study of Papua New Guinea, world-renowned facial expression researcher Paul Aikman found that tribes like the Alpine tribes had no contact with Western culture at all, and that tribes with cannibalistic habits would smile when they heard the slightest laugh