Georgetown University

Washington, D.C. – Nonverbal dominance displays in many non-human species are known to increase the displayer’s apparent size. Now researchers led by assistant professor of psychology Abigail Marsh have found that humans also employ a variety of nonverbal cues that make them appear larger or smaller. Physical size, the researchers say, is closely linked to social dominance.

Marsh and her team report their findings in an article published in the May 27, 2009 edition of the journal PLoS ONE.

While several psychological studies previously have demonstrated that physical size affects perceptions of status and that status alters perceptions of physical size, “No prior study has assessed whether human nonverbal cues can, like the nonverbal cues of non-human animals, create the appearance of changes in physical size that influence the displayer’s perceived status,” says Marsh, who directs the Georgetown Laboratory on Social and Affective Neuroscience. “Our study suggests that certain nonverbal dominance cues in humans may function as they do in other species by creating the appearance of changes in physical size.”

Citing existing research, the authors argue that social dominance and physical size are inextricably linked.

“In species ranging from montane lizards to mountain gorillas, physical size is a direct and primary determinant of social dominance, with physically larger animals attaining greater social status than smaller animals,” they write. “Appearing larger may enhance social dominance because larger appearing opponents are more likely to spur an opponent to withdraw and thus win by forfeiture.”

Social dominance facilitates success in competition for territory, reproduction, and survival in many species. Greater physical size enhances human and non-human animals’ ability to attain these goals. In humans, physical size also confers advantages in social dominance and the acquisition of resources. Supporting this claim, the authors cite research that taller men earn more money (as much as $600 per inch) and achieve higher job status and that 10 of the 12 United States presidential elections from 1952 to 1996 were won by the taller candidate.

Marsh and her colleagues show that high status and low status cues lead to changes in apparent physical size and that body postures and other nonverbal cues alter people’s apparent size. The difference in perception predicts how effective individuals are in conveying social dominance or subordination. Marsh says these results suggest parallel functions in the nonverbal dominance cues of humans and other animals.

In the study, participants judged people in a variety of poses on apparent height, weight and dominance. The high status cues shown to be highly indicative of perceived dominance include lowered brows, direct gaze, open body posture, and outwardly-directed gestures, such as pointing. Low status variants of these cues included raised brows, averted gaze, closed posture and self-directed gestures such as touching one’s own neck.

“Our results demonstrate convergence between human behaviors and the status displays of non-human animals and highlight the importance of low-level perceptual processes in shaping some of the complex processes that underlie human social behavior,” says Marsh.

After the embargo lifts the full text of the PLoS ONE article will be freely available online at http://www.plosone.org/.

About the Georgetown Laboratory on Social and Affective Neuroscience
Research in the Georgetown Laboratory on Social and Affective Neuroscience is aimed at understanding aspects of human social interactions and emotional functioning using cognitive neuroscience methods. The lab is particularly focused on nonverbal communication and empathy and other research includes studies with healthy and clinical populations of adolescents and adults, incorporating neuroimaging, cognitive and behavioral testing and pharmacological techniques. For more information, visit www.abigailmarsh.com/.

About PLoS
The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical research a public resource. PLoS publishes open-access journals of original peer-reviewed research including PLoS Biology and PLoS Medicine, available at no cost to anyone in the world with a connection to the Internet. More information can be found at www.plos.org and www.plosone.org.

About Georgetown University
Georgetown University is the oldest and largest Catholic and Jesuit university in America, founded in 1789 by Archbishop John Carroll. Georgetown today is a major student-centered, international, research university offering respected undergraduate, graduate and professional programs in Washington, D.C., Doha, Qatar and around the world. For more information about Georgetown University, visit www.georgetown.edu.