People can make trustworthiness judgements based on facial characteristics. However, the previous findings regarding on whether facial age influences interpersonal trust are inconsistent. Using the trust game, the current study investigated the interactions of facial age with attractiveness and emotional expression in regarding to trustworthiness judgements. In experiments 1 & 2, younger participants were asked to invest in either younger or older faces that were shown for 2000 ms and 33 ms respectively. The results showed that people trust the faces of older people more than they do of younger people. There was also an interaction between facial age and attractiveness. The participants invested more money in older faces than in younger faces only when they perceived the faces to be less attractive. However, the interaction between facial age and emotional expression was inconsistent in the two experiments. The participants invested more money in older faces that were shown for 2000 ms when they perceived the happy and sad emotions, but they invested more money in older faces that were shown for 33 ms when they perceived the happy emotion. These results reveal that people make trustworthiness judgements based on multiple facial cues when they view strangers of different ages.

People can judge a stranger's trustworthiness at first glance solely based on facial appearance. Moreover, the trust behaviors people exhibit toward strangers differ depending on perceived trustworthiness from faces. Research has found that people have different risk preferences according to the gain or loss frame. Therefore, we hypothesized that the risk decisions are differently affected by facial trustworthiness in different frames. We conducted three experiments in which we asked participants to make risk decisions in the gain frame or loss frame. The results revealed that facial trustworthiness had a significant effect on risk decisions in the gain frame. However, the effect was attenuated in the loss frame. These results suggest that people are more willing to take risks in the gain frame if individuals look more trustworthy than those who look untrustworthy.

In real life, people perceive non-existent faces from face-like objects, called face pareidolia. Face-like objects can capture the observer’s visual attention and trigger attentional shifts like faces. However, studies do not determine whether attentional shifts induced by face-like objects are stemmed from social or symbolic information. Furthermore, the similarities and differences in the occurrence mechanism of attentional shifts induced by face and face-like objects remain unknown. To investigate this research question, our study used the gaze cueing task to compare the magnitude of cueing effects found in face-like objects and averted gaze faces. Our results suggested that both face-like objects and averted gaze faces triggered attentional shifts, although the underlying mechanisms differed. Specifically, individuals could make attentional shifts via processing local features on both averted gaze faces and face-like objects. However, unlike averted gaze faces, individuals tend to process the holistic features of face-like objects to enhance the subsequent cueing effect. These findings provide new insight into the occurrence mechanisms underlying the perception of face-like objects, and how the brain represents a face even in the absence of physical facial stimuli.