Verbal and nonverbal behaviour as a basis for credibility attribution: The impact of task involvement and cognitive capacity

Three experiments were able to demonstrate the usefulness of dual-process models for the understanding of the process of credibility attribution. According to the assumptions of dual-process models, only high task involvement and high cognitive capacity leads to intensive processing of verbal and nonverbal information when making credibility judgments. Under low task involvement and/or low cognitive capacity, people predominantly use nonverbal information for their credibility attribution. In Experiment 1, participants under low or high task involvement saw a film in which the nonverbal behaviour (fidgety vs. calm) and the verbal information (low versus high credibility) of a source were manipulated. As predicted, when task involvement was low, only the nonverbal behaviour influenced participants’ credibility attribution. Participants with high task involvement also used the verbal information. In Experiment 2 and 3, the cognitive capacity of the participants was manipulated. Participants with high cognitive capacity, in contrast to those of low cognitive capacity, used the verbal information for their credibility attribution.