We can show a lot about ourselves through our eyes during conversation. Do we need to make direct eye contact with each other though, or is just looking at each other's faces sufficient for communication?
Researchers in Canada found pairs of people in conversation rarely engaged in mutual looking (each participant looking at their partner's face at the same time). The amount of eye-to-eye contact was even rarer, but the little that occurred predicted participant's likelihood to follow the other person's gaze as the conversation flows on.
Mutual looking is one of the most basic nonverbal communication behaviors but it's not well studied, the team explains, partly because previously available mobile eye-tracking technology has limited measurement of eye movement during real-life interactions.
"This study is one of the first to show the prevalence of eye-to-eye looking during real-life interactions," says first author Florence Mayrand, an experimental psychologist at McGill University in Canada.
"We found that, surprisingly, direct eye-to-eye contact was quite rare during interactions, but that it is significant for social dynamics. The time we engage in eye-to-eye contact, even if for a few seconds, appears to be an important predictive factor for subsequent social behavior."
Mayrand and her colleagues looked at eye-gazing patterns during face-to-face conversations between 15 pairs of strangers, made up of 25 women and 5 men, all between the ages of 18 and 24.
The pairs ranked 12 items in order of usefulness in a made-up survival situation while wearing mobile eye-tracking glasses with a front-facing camera recording their field of view. The researchers recorded how often the participants looked at each other's mouths and eyes.
In a second test, they measured each individual's gaze in reaction to an image of their partner's face looking in different directions.
Eye tracking issues limited their final analysis to 12 females and 2 males in 7 pairs.
During the interactions, each participant looked away more than they looked directly at their partner's face. When they did look at each other's face, they looked mostly at the mouth and eye regions and rarely engaged in mutual eye-to-eye contact. Eye-to-mouth mutual-looking was the most common.
Past research indicates eye contact is important in communication, so this came as a surprise, and the gaze behavior contradicts other studies in three- or four-person groups.
"We discovered that participants spent only about 12 percent of conversation time in interactive looking, meaning that they gazed at each other's faces simultaneously for just 12 percent of the interaction duration," Mayrand says.
"Even more surprisingly, within those interactions, participants engaged in mutual eye-to-eye contact only 3.5 percent of the time."
But when pairs did look directly into each other's eyes, one of them was more likely to follow their partner's gaze in the follow-up test. Mayrand and team also linked eye-to-mouth mutual looks to a tendency to follow their partner's gaze in the second experiment.
The amount of time people spend looking each other in the eyes may be important for communicating social messages between them, the researchers say, and different mutual looking patterns may be useful for relaying specific messages in different combinations.
It's worth noting the list-making task participants completed together in this study may not have been as conducive of numerous mutual glances between faces as other tasks might be. Most did look at each other, but via non-mutual looking rather than in unison.
The team says it would be interesting to study in the future how conversational context affects how people look at each other's faces.
The sample size was quite small, so larger studies may turn up broader results. Another possibility is that gaze dynamics may be different when people are with friends instead of strangers.
"The context of the social messages communicated by the eyes remains a highly interesting research question for future work," the authors conclude.
The study has been published in Scientific Reports.