Women follow the gaze of a familiar face more readily than men do, researchers suggest, after carrying out a curious, small study.

Michael Platt at Duke University Medical Center in Durham, North Carolina, US, and colleagues asked 32 volunteers to watch a screen that showed the face of either a stranger or a colleague looking to the right or left for 200 milliseconds (one-fifth of a second). The participants then waited to see whether a dot appeared on the right or left of a screen, and pressed one of two buttons accordingly.

Under all conditions, women in the study were slightly slower than the men to push the buttons, the team found. But when a familiar onscreen face looked at the side opposite to which the dot appeared, the women performed even worse – taking about 24 milliseconds longer than men to press the button, on average. In cases where the familiar face gazed toward the side where the dot then appeared women lagged behind men by only 10 milliseconds.

Although the experiment involved few subjects, and all the onscreen faces were all of men, Platt believes it is possible to draw some general conclusions from the findings. He says the results suggest that women follow the attention of familiar faces more closely than men do, and that brain differences between men and women might account for this finding.


Potential skew

Previous studies have shown that the brain regions that process facial expressions – including the amygdala and obritofrontal gyrus – are highly sensitive to sex hormones. But Platt stresses it remains unclear whether potential brain differences are innate or the product of environmental influences.

He does admit that since all of the “familiar” faces used in the experiment were pictures of men, the results could be skewed. We hope to conduct similar experiments in the future using familiar female faces, he adds.

More experiments are needed to find out why the gaze of familiar faces influences women more than men, Platt’s team says. They claim that understanding this difference could shed light on the causes of autism, which affects four times more males than females.

Journal: Biology Letters (DOI: 10.1098/rsbl.2006.0564)