Making eye contact, long considered an effective way of persuasion, might be counterproductive when the listeners already disagree, according to a new study.

The study, published recently in Psychological Science, a journal of the Association for Psychological Science, was the result of collaborations among researchers from Canada, Germany and the United States.

"There is a lot of cultural lore about the power of eye contact as an influence tool," said University of British Columbia Prof. Frances Chen, one of the first authors of the study. "But our findings show that direct eye contact makes skeptical listeners less likely to change their minds, not more, as previously believed."

With the help of recently developed eye-tracking technology, the researchers investigated the effects of eye contact in situations involving persuasion in a series of experiments.

They found that on various controversial issues, the more participants watched a speaker's eyes, the less persuaded they were by the argument of the person speaking.

Spending more time looking at someone's eyes as they spoke was only associated with greater receptiveness among participants who already agreed with the speaker on that issue, according to the researchers.

"Whether you' re a politician or a parent, it might be helpful to remember that trying to maintain eye contact may backfire if you' re trying to convince someone who has a different set of beliefs than you," said co-author Julia Minson of Harvard's Kennedy School of Government.