Guided by interpersonal deception theory and the principle of interactivity, this investigation examined whether communication modalities differentially affect the extent to which group members develop trust or are vulnerable to manipulation and deceit, based on the degree of interactivity the modalities afford. According to the principle of interactivity, involvement and mutuality should increase as one moves from text, to audio and audiovisual (AV) modalities, to face-to-face (FtF) communication. Under nondeceptive circumstances, greater interactivity should elicit corresponding increases in trust and credibility; under deceptive circumstances, it should produce greater truth biases and inaccurate detection of deceit. This effect should be partly mitigated in text and audio modalities due to the presence of diagnostic deception indicators Pairs were assigned to a truthful or deceptive condition in one of three mediated conditions, or in a face-to-face condition. In the deceptive condition, one member of each pair was enlisted to deceive during the interaction. Following discussion, participants rated their communicative behavior and the credibility of the truthful or deceptive actor. Truth bias and accuracy in judging deceptive information was calculated. Results are compared to previous findings from face-to-face deception. Implications for collaborative technologies are advanced.