The Multimodal Trust Effects of Face, Voice, and Sentence Content

Abstract Trust is an aspect critical to human social interaction and research has identified many cues that help in the assimilation of this social trait. Two of these cues are the pitch of the voice and the width-to-height ratio of the face (fWHR). Additionally, research has indicated that the content of a spoken sentence itself has an effect on trustworthiness; a finding that has not yet been brought into multisensory research. The current research aims to investigate previously developed theories on trust in relation to vocal pitch, fWHR, and sentence content in a multimodal setting. Twenty-six female participants were asked to judge the trustworthiness of a voice speaking a neutral or romantic sentence while seeing a face. The average pitch of the voice and the fWHR were varied systematically. Results indicate that the content of the spoken message was an important predictor of trustworthiness extending into multimodality. Further, the mean pitch of the voice and fWHR of the face appeared to be useful indicators in a multimodal setting. These effects interacted with one another across modalities. The data demonstrate that trust in the voice is shaped by task-irrelevant visual stimuli. Future research is encouraged to clarify whether these findings remain consistent across genders, age groups, and languages.