Abstract: The human face is among the most important visual stimuli for people of all ages, the importance of which partly stems from the face as a conveyer of information on emotional states of other individuals. Previous studies have verified that faces with threat-related expressions (anger or fear) tend to be more attractive than neutral ones. These studies suggest that the visual preference of the facial expressions support the threat-detection theory. On the other hand, recent findings show that positive faces, but not threat-related faces are more efficiently detected in visual search tasks, which seems to support another theory, the social emotional selectivity theory. So, which one of the two theories above is more capable of explain the developmental characteristics of visual preference of facial expressions? The question calls for a study comparing adults and children. The two hypothesis of the study are: (1) Due to the increase in the dependence of social interaction, there is a significant difference in preferred expression types in terms of attention characteristics between children and adults, with the latter preferring positive expressions. (2) There is a significant difference in preferred facial parts of an expression between adults and children, which, if verified, should provide empirical evidence in favor of the social emotional selectivity theory. Facial parts of fixation and its lengths, often assumed to directly reflect the allocation of visual attention, also play important roles in the visual preference of facial expression. In this study, an eye-tracker was employed to look into the developmental characteristics of both children and adults’ viewing of facial expressions. 45 children and 39 undergraduate subjects enrolled were instructed to view pictures of 5 different facial expressions, which were fear，anger, sadness, surprise and happiness, and their eye movements were recorded with a Tobbi eye tracker during the process. The results analyzed with ANOVA show that there are differences in adults and children’s visual preference of emotional expressions. First, the preference to happy expressions by adults is not observed in children. Second, adults make more and longer fixations in viewing happy faces compared to children. Third, adults are more likely to look at the eyes but children are more likely to look at the mouth. The study suggests that human expression of happiness has become more visually preferred by adults as a result of evolution, because the social dependency of positive emotions is less ambiguous than other facial expressions, and the visual preference of different facial parts could be related to these developmental changes.

Key words: facial expression, visual preference, eye movement

摘要： 本研究选取45名3-5岁幼儿和39名大学本科生作为被试。实验材料为恐惧、愤怒、悲伤、惊讶和高兴五种面部表情图片。用Tobbi眼动仪记录被试观察表情图片时的眼动轨迹。结果发现：（1）成人偏好高兴表情，并在高兴表情上的注视时间和次数显著大于幼儿；（2）成人偏好注视眼部，幼儿偏好注视嘴部。结果表明，面部表情注意偏好的发展具有社会依存性，趋向于偏好积极情绪，这种发展变化与面部表情部位的注意偏好相关。

关键词: 面部表情, 注意偏好, 眼动