Pupil size reflects the cognitive and affective states of the beholder and thus shapes interpersonal impressions. Individuals with dilated pupils are evaluated more positively than those with constricted pupils. The present study investigated the role of pupil dilation in building interpersonal trust. We used face photographs taken by Okubo et al. (2017), in which models (N = 81) were posed as trustworthy persons for a photograph shown in an economic game. We measured the pupil diameter of each model’s photographs using image processing software. The pupils were dilated when the models expressed trustworthiness in their faces. Moreover, untrustworthy choices in an economic game predicted pupil dilation. As dilated pupils produce positive impressions, the results suggest that pupil dilation may be associated with concealing signals of trustworthiness. Untrustworthy individuals may use pupillary responses almost incapable of voluntary control to exploit others in social interactions.

瞳孔大小反映了旁观者的认知和情感状态，从而塑造了人际印象。瞳孔散大的个体比瞳孔收缩的个体得到更积极的评价。本研究调查了瞳孔放大在建立人际信任中的作用。我们使用了 Okubo 等人拍摄的面部照片。（2017），其中模型（N = 81) 被假装为经济游戏中显示的照片的值得信赖的人。我们使用图像处理软件测量了每个模特照片的瞳孔直径。当模特们在脸上表现出信任时，瞳孔放大了。此外，经济游戏中不可信的选择预示着瞳孔放大。由于放大的瞳孔会产生积极的印象，结果表明瞳孔放大可能与隐藏可信赖的信号有关。不值得信任的人可能会使用几乎无法自主控制的瞳孔反应来在社交互动中利用他人。