For the study, Michael LaCour of UCLA and Donald Green of Columbia surveyed a bunch of registered voters in Southern California to get their views on gay marriage (and a bunch of other issues, to hide the true purpose of the study), and offered them financial incentives to get friends and family members to participate as well.
Then, trained canvassers were dispatched to the homes of the people who had taken the survey, where they delivered a script about either gay marriage or recycling (to create a placebo group) and asked the voters to express their opinions on the subject. Halfway through the conversations about gay marriage, the gay canvassers revealed they were gay and wanted to get married but couldn’t because of California’s then-ban on gay marriage, while the straight ones “instead described how their child, friend, or relative” was dealing with the same conundrum. The conversations lasted, on average, 22 minutes…
In the short term, the 20-minute conversations about gay marriage had a clear and large effect: Before the conversation, the residents had held beliefs on gay marriage in line with the average resident of Nebraska or Ohio; a few days after, their beliefs were in line with the average residents of Connecticut and Massachusetts (an increase of 0.48 points on a 5-point scale), and whether the canvasser was gay or straight didn’t have much impact on the size of the effect.
But it was the longer-term effect that was more surprising: While “90% of the initial treatment effect dissipated a month after the conversation with canvassers” among voters who spoke with a straight canvasser, among those who conversed with a gay canvasser, the size of the effect increased over time — “ only gay canvassers’ effects persisted in 3-week, 6-week, and 9-month follow-ups.” By the end of the study, among voters who spoke with a gay canvasser, the gap between where they were and where they ended up on the issue of gay marriage was equivalent to the difference in opinion on the subject between the average resident of Georgia and the average resident of Massachusetts.
For more, go here.