by Jeff Grabmeier
When you nod your head to signal approval or shake your head to show disapproval, it’s not just sending a message to others – you may also be influencing yourself. A new study showed that these simple movements influenced people’s agreement with an editorial they heard while nodding or shaking their head.
When you nod your head to signal approval or shake your head to show disapproval, it’s not just sending a message to others – you may also be influencing yourself.
A new study showed that these simple movements influenced people’s agreement with an editorial they heard while nodding or shaking their head. Researchers found that other body movements – such as writing with a non-dominant hand – can also influence attitudes, even about important issues such as self-esteem.
And these body movements exert their influence without people being aware of what is happening.
“We think of nodding or shaking our head as something that communicates to other people, but it turns out that it is also communicating to ourselves,” said Richard Petty, co-author of the study and professor of psychology at Ohio State University.
In a sense, Petty said, nodding or shaking your head, as well as other body movements, serve as a kind of “self-validation” that confirms to us how we feel about our own thoughts.
“If we are nodding our heads up and down, we gain confidence in what we are thinking. But when we shake our heads from side to side, we lose confidence in our own thoughts.”
Petty conducted the study with Pablo Brinol, a former doctoral student at Ohio State now at the Universidad Autonoma de Madrid in Spain. The research appears in the current issue of the Journal of Personality and Social Psychology.
In one study, the researchers told 82 college students that they were testing the sound quality of stereo headphones – particularly how the headphones would perform when they are being jostled, as during dancing or jogging.
Half the participants were told to move their heads up and down (nodding) about once per second while wearing the headphones. The other half was told to move their heads from side to side (shaking) while listening on the headphones.
All of the participants listened to a tape of a purported campus radio program that included music and a station editorial advocating that students be required to carry personal identification cards.
After listening to the tape, the participants rated the headphones and gave their opinions about the music and the editorial that they heard.
The study found that head movements did affect whether they agreed with the editorial. But the effect is more complicated than might be expected.
The study found that nodding your head up and down is, in effect, telling yourself that you have confidence in your own thoughts – whether those thoughts are positive or negative. Shaking your head does the opposite: it gives people less confidence in their own thoughts.
So participants in this study who heard an editorial that made good arguments agreed more with the message when they were nodding in a “yes” manner than shaking in a “no” manner. This is because the nodding movements increased confidence in the favorable thoughts people had to the good arguments compared to shaking.
However, students who heard an editorial that made poor arguments showed the reverse pattern. These students agreed less with the message when they were nodding than when shaking. This is because the nodding movements increased confidence in the negative thoughts they had to the poor arguments compared to shaking.
