Faces in the wild: A naturalistic study of children’s facial expressions in response to an Internet prank

There is surprisingly little empirical evidence supporting theoretical and anecdotal claims regarding the spontaneous production of prototypic facial expressions used in numerous emotion recognition studies. Proponents of innate prototypic expressions believe that this lack of evidence may be due to ethical restrictions against presenting powerful elicitors in the lab. The current popularity of internet platforms designed for public sharing of videos allows investigators to shed light on this debate by examining naturally-occurring facial expressions outside the laboratory. An Internet prank (“Scary Maze”) has provided a unique opportunity to observe children reacting to a consistent fear- and surprise-inducing stimulus: The unexpected presentation of a “scary face” during an online maze game. The purpose of this study was to examine children’s facial expressions in this naturalistic setting. Emotion ratings of non-facial behaviour (provided by untrained undergraduates) and anatomically-based facial codes were obtained from 60 videos of children (ages 4–7) found on YouTube. Emotion ratings were highest for fear and surprise. Correspondingly, children displayed more facial expressions of fear and surprise than for other emotions (e.g. anger, joy). These findings provide partial support for the ecological validity of fear and surprise expressions. Still prototypic expressions were produced by fewer than half the children.

现有关于情绪识别研究中广泛使用的原型面部表情（prototypic facial expressions）自发产生的理论与轶事式主张，却鲜有实证证据予以支撑，这一点颇为出人意料。主张先天原型面部表情存在的学者认为，此类证据缺失或许源于实验室中呈现强情绪诱发刺激所面临的伦理限制。当前面向公众分享视频的互联网平台的普及，为研究者跳出实验室框架，探究自然情境下的面部表情提供了契机，从而为这一争论带来新的洞见。一项名为‘恐怖迷宫’（Scary Maze）的网络恶作剧为研究者提供了独特契机，得以观察儿童对一致性恐惧与惊讶诱发刺激的反应：在线迷宫游戏过程中，意外呈现一张‘恐怖鬼脸’。本研究旨在探究这一自然情境下儿童的面部表情表现。研究人员从YouTube平台上获取的60段4至7岁儿童视频中，提取了未经训练的本科生对非面部行为的情绪评分，以及基于解剖学特征的面部编码。情绪评分结果显示，恐惧与惊讶情绪的得分最高。相应地，相较于其他情绪（如愤怒、喜悦），儿童展现出更多的恐惧与惊讶类面部表情。上述研究结果为恐惧与惊讶表情的生态效度提供了部分支撑。但即便如此，仅有不足半数的儿童产生了原型面部表情。