'Genius is 1% inspiration and 99% perspiration'... or is it? An investigation of the impact of motivation and feedback on deception detection

Purpose. Although most people perform around the level of chance in making credibility judgments, some researchers have hypothesized that high motivation and the provision of accurate feedback could lead to a higher accuracy rate. This study examined the influence of these factors on judgment accuracy and whether any improvement following feedback was related to social facilitation, a gradual incorporation of successful assessment strategies, or a re-evaluation of 'tunnel vision' decision-making. Methods. Participants (N = 151) were randomly assigned to conditions according to motivation level (high/low) and feedback (accurate, inaccurate or none). They then judged the credibility of 12 videotaped speakers either lying or telling the truth about a personal experience. Results. Highly motivated observers performed less accurately (M = 46.0%), but more confidently, than those in the low-motivation condition (M = 60.0%). Although there was no main effect of feedback, the provision of any feedback (accurate or inaccurate) served to diminish the motivational impairment effect. Further, high motivation was associated with a relatively low 'hit' rate and high 'false-alarm' rate. This suggested that in the absence of feedback the judgments of highly motivated participants were made through tunnel vision. Conclusions. The results suggest that it is important for lie-catchers to monitor their motivation level to ensure that over-enthusiasm is not clouding their judgments. It may be useful for professionals engaged in deception detection to regularly discuss their judgments with colleagues as a form of feedback in order to re-evaluate their own decision-making strategies.