A study by William Chaplin, Jeffrey Phillips, and colleagues, reported in the Journal of Personality and Social Psychology, found that how you shake hands alters people’s impressions of you—and relates to your actual personality.
First, four judges were trained to assess eight characteristics of a handshake, including completeness of grip, temperature, dryness, strength, duration, vigor, texture, and eye contact. The raters received a month of training that included learning how to extend their hands at a neutral 45-degree angle, how to follow the lead of the other person’s handshake, and how to understand the eight dimensions of handshakes. Then they rated the handshakes of 112 undergraduate participants—half male, half female.
First, a rater welcomed an undergraduate to the lab with a handshake. Then the rater explained that this research is aimed at determining whether people's answers on personality scales differ if the scales are administered all at once or in separate settings. The rater went on to explain that the student would be taking the scales in several different rooms. The rater then seated the student and asked him or her to complete the first scale. Once finished, the first rater sent the student to a new room. There, a second rater greeted the participant—with a handshake—and asked the student to complete a second personality scale. This process was repeated until four separate raters had shaken hands with the participant (and the participant had completed all the scales).
Each time a rater shook hands with a participant, the rater covertly assessed his or her handshake along the eight dimensions (firmness, eye-contact, and so on). The actual research hypotheses were whether handshake style was consistent across raters and whether the qualities of the participants' handshake styles correlated with key aspects of their personalities.
The researchers first examined the ratings of the eight dimensions of handshaking and discovered that they rose and fell together across people—that is, people high in firmness and duration also tended to have a good grip and make good eye contact; people whose handshakes were less firm performed less well on the other dimensions. A given handshake could therefore be characterized accurately across the rated qualities by a single composite score—a "firm handshake."
Our parents were right.
The raters generally agreed as to which participants' handshakes were firm and which were not, indicating the consistency of the participants' style over multiple handshakes. Participants with firmer handshakes described themselves on the personality measures as more open, extroverted, and positive than others, and less shy and neurotic. The evaluators, who had recorded their own impressions of the students, agreed that the participants with firmer handshakes were more positive and outgoing, and less socially anxious.
Bonus Handshake Study
Greg Stewart and Susan Dustin of the University of Iowa and their collaborators found that raters could also agree on the quality of a job applicant’s handshake. In their study, undergraduates showed up for a mock job interview with a human resource professional. On arrival, two raters greeted the applicant with handshakes and then introduced him or her to a third rater, who also shook hands (de rigueur). Each rater then evaluated the students' handshakes.
Next, applicants went to a mock job interview with one of several human resource professionals from companies near the college. After the interview, a fourth rater shook hands with the interviewee as he or she prepared to leave—and introduced the applicant to yet a fifth rater who also shook hands. These post-interview raters also evaluated the applicant's handshake. The human resource professionals—who were unaware of any interest in handshakes—evaluated the applicants based on their interview.
The key finding: Applicants with firm handshakes had stronger “hire” recommendations.
Bernieri, Frank J. Petty, Kristen N. (2011). The influence of handshakes on first impression accuracy. Social Influence, 6(2), 78-87.
Mayer, J. D. (2014). Personal intelligence: The power of personality to shape our lives. New York: Scientific American/Farrar Strauss & Giroux