Do Not Skip that Handshake: How Body Language Shapes Our Judgments

We all know that a proper business meeting should start with a handshake but until now, we have not known exactly how much impact that seemingly small gesture can make. Turns out, the impact is substantial, according to new research that examines the neurological and emotional effects of a handshake.

“Handshakes have been proven to increase the perception of trust and formality of the relationship, and a handshake initiated by a female has been shown to increase the perceived feeling of security when making risky financial decisions,” says Sanda Dolcos of the University of Illinois, who presented new research this week at the Society for Neuroscience annual meeting in New Orleans. “Yet, the study of interpersonal and emotional effects of handshake, and the associated neural correlates, has been largely neglected.”

Therefore, Dolcos and colleagues set out to study the crucial role handshakes, as well as other body language, plays in how we evaluate social interactions. Unlike past research on this topic, they designed scenarios that would use dynamic social stimuli as opposed to static ones (such as faces), combined with behavioral measures to link to brain imaging data.

Participants watched a series of 10-second videos that showed a host greeting a guest with body language to show either approach or avoidance behaviors. In the approach condition, a host stepped toward the guest while displaying an “open/inviting” posture with open arms and smiling face. In the avoidance condition, the host stepped away while displaying a “closed/noninviting” posture with crossed arms/legs and a grimace on the face. Unanimated hosts were used for the control condition for no social interaction. In half the social interaction videos, hosts preceded the greeting with a handshake.

Researchers measured the brain activity of the participants while watching the videos and then asked the subjects to rate the hosts on “competence,” and “trustworthiness,” as well as their own “interest in doing business” with the host.” In general, participants rated the approach condition more favorably than the avoidance one. And, to the researchers’ surprise, the handshake not only improved the favorable rating for the approach condition but also reduced the negative impression of the avoidance condition.

“This finding is very important, as it suggests that handshake preceding social interactions not only can increase the positive impact of good impressions but can also reduce the negative impact of bad impressions,” Dolcos says. “Many of our social interactions may go wrong for a reason or another, and a simple handshake preceding them can give us a boost and attenuate the negative impact of possible misshapenings.”

The researchers also found that common brain regions in the social cognition network were involved in the evaluation of the approach and avoidance conditions. Specifically, the results showed that positive evaluation of the approach behavior and the positive impact of the handshake were linked to increased sensitivity in the amygdala and superior temporal sulcus. And they found greater activity in the nucleus accumbens for the handshake than for the no-handshake condition.

Overall, these findings not only replicated previous reports that identify activity in regions of the social cognition network, but also provided insight into the contribution of these regions into evaluating approach and avoidance social interactions, and grant neuroscientific support for the power of a handshake, the authors say. “Our study identifying the behavioral and neural correlates of handshake is giving insight into just how important the practice is in the evaluations we make of subsequent social interactions,” Dolcos says.

Next, Dolcos and colleagues plan to investigate the effects of other common gestures used in various social interactions. Dolcos also is interested in the the role of cultural aspects in social interaction.

-Lisa M.P. Munoz

The paper – “The Power of a Handshake: Neural Correlates of Evaluative Judgments in Observed Social Interactions,” Sanda Dolcos, Keen Sung, Jennifer J. Argo, Sophie Flor-Henry, and Florin Dolcos – was published in the Journal of Cognitive Neuroscience, online on September 27, 2012.

Media contact: Lisa M.P. Munoz, CNS Public Information Officer, cns.publicaffairs@gmail.com