Everybody knows that what candidates say in an interview is important. But, despite decades of research and ongoing popular interest, it remains unclear which nonverbal cues displayed in the interview have the greatest impact on hiring decisions. Because studies can reach different conclusions, the "big picture" can be hard to see. However, statistical methods help us to resolve the uncertainty produced by inconsistent results.

We draw on what researchers call "dual-process theory" in understanding the role of nonverbal cues in hiring interviews. This theory says that when making decisions, people can be quick and intuitive, or they can stop and think more effortfully about the information at hand. Decision-making is thus influenced on the one hand by low-effort, quick, non-conscious thoughts and mental shortcuts and on the other hand, by deliberate, slow, systematic thoughts. We predicted that in most cases interviewers largely rely on the quick, subconscious decision process, based on the nonverbal cues the applicant displays in the interview. However, we also predicted that some characteristics of the interview (such as whether the study was conducted in an experimental research setting or out in a realistic field setting, or the interviewee's gender) would prompt interviewers to use the more effortful and deliberate style of making hiring decisions.

My research colleagues and I analyzed 63 independent studies to test our predictions. We were able to connect the results of the studies to how they were designed and who was in them. Our findings showed that interviewees' appearance, movement, and voice affected judgments of how well they performed during job interviews and, thus, the likelihood of them being hired. Professional appearance was the most powerful predictor of interview performance. An applicant's clothing can be used to make inferences about the wearer, and in situations where little information about the wearer is available, dress can carry increased weight in influencing an observer's perceptions.

Applicants' eye contact and head movement in an interview are also very important. Research suggests that interviewers infer trustworthiness, sincerity, conscientiousness, and even intelligence based on sustained eye contact. Similarly, head movements are often taken as signs of an individual's attentiveness and engagement in a conversation. Vocal characteristics are also related to interview performance, where attractive voices are ones that display a pleasant and varied combination of loudness, speech rate, and pitch. Voice quality can be difficult for people to change, limiting candidates' ability to improve this aspect of their interview performance. Finally, interviewees' stigmatized appearance (e.g., port wine stains, pregnancy, visible tattoos, etc.) was the only nonverbal cue negatively related to hiring decisions.

Organizations may increase the use of more thorough and deliberate thinking in interview evaluations by requiring interviewers to engage in more effortful mental deliberation, perhaps through the use of a more detailed interview evaluation rubric, to reduce bias against stigmatized applicants.

We also found that the gender of the interviewee played an important role in the effect of most, but not all, nonverbal cues on interview performance. Studies with more women than men demonstrated stronger effects of professional appearance and facial expressions on interview ratings. Thus, women may be rewarded in their interview ratings more than men for how they dress (professional appearance) and for their facial expressions (eye contact and smiling). This underscores the power of superficial thinking in affecting interviewer evaluations of applicants, and suggests that such judgments may reflect pervasive stereotypes about women—that they should be more emotive, expressive, and affiliative than men.

Finally, we found that the effect of nonverbal cues on interview performance is stronger in experimental, laboratory-based studies than in observational studies usually done out in the field. This may have occurred because many experimental studies use simulated interviews in low-stakes settings where the "applicant's" motivation to effectively respond may be lacking, which could artificially inflate the effect of nonverbal cues on hiring decisions.

Our review answers a near-century-old question: What impact do specific nonverbal cues have on interview performance? The answer we found is not the end, but rather, a beginning. The focus should now turn to the study of more fine-grained types of nonverbal cues in interviews and how well they predict hiring decisions, as well as the comparison of different types of jobs and employment settings.

For Further Reading

Martín‐Raugh, M. P., Kell, H. J., Randall, J. G., Anguiano‐Carrasco, C., & Banfi, J. T. (2022). Speaking without words: A meta‐analysis of over 70 years of research on the power of nonverbal cues in job interviews. Journal of Organizational Behavior, 1-25. DOI: 10.1002/job.2670

Michelle Martín-Raugh is an Assistant Professor of Psychology and director of the Employee Assessment, Selection, and Training (EAST) Lab at the University of Texas at Arlington. Research conducted in the EAST Lab explores assessments (e.g., situational judgment tests [SJTs], video-based interviews, performance-based team tasks) for use in hiring and training employees.