NEW YORK — For years, backers of same-sex marriage have said more voters would support it if only they could hear directly from gay people with a personal stake in the issue. A new academic study bears out that hunch.

In an article released Thursday by Science magazine, researchers from Columbia University and the University of California-Los Angeles detail a rigorous study which found that openly gay canvassers were far more effective than straight canvassers in shifting voters’ views toward support for same-sex marriage.

The canvassers, 22 of them gay and 19 of them straight, were recruited and trained by the Los Angeles LGBT Center and had similar one-on-one conversations in June 2013 with 263 voters in Southern California precincts that had supported a still-in-effect state ban on gay marriage.

The only difference was that the gay canvassers revealed midway through the conversations – which averaged 22 minutes in length – that they were gay and wanted to get married, but were barred from doing so.

According to follow-up surveys, opinion changes produced by the straight canvassers tended to fade within a few weeks and those voters reverted to their previous views less favorable to same-sex marriage.

However, the changes produced by the gay canvassers persisted nine months later, and the change in attitude often spread to other members of the voters’ households who weren’t part of the canvassing conversations.

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And the magnitude of that change was significant. The researchers, Columbia political science professor Donald Green and UCLA doctoral student Michael LaCour, said it was as if views typical of conservative Georgia changed to those of liberal Massachusetts.

LaCour, the study’s lead author, said he hopes to test whether a similar approach of in-depth conversations could shift people’s attitudes toward immigrants who are in the U.S. illegally.

Green said the tactic might prove useful in other causes – for example, trying to shift views on abortion via a one-on-one encounter with a woman grateful she had access to a legal abortion or with a woman who regretted having the procedure.