Nonverbal communication is an important part of human communication, including head nodding, eye gaze, proximity and body orientation. Recent research has identified specific patterns of head nodding linked to conversation, namely mimicry of head movements at 600 ms delay and fast nodding when listening. In this paper, we implemented these head nodding behaviour rules in virtual humans, and we tested the impact of these behaviours, and whether they lead to increases in trust and liking towards the virtual humans. We use Virtual Reality technology to simulate a face-to-face conversation, as VR provides a high level of immersiveness and social presence, very similar to face-to-face interaction. We then conducted a study with human-subject participants, where the participants took part in conversations with two virtual humans and then rated the virtual character social characteristics, and completed an evaluation of their implicit trust in the virtual human. Results showed more liking for and more trust in the virtual human whose nodding behaviour was driven by realistic behaviour rules. This supports the psychological models of nodding and advances our ability to build realistic virtual humans
