A new experiment finds that door-to-door persuasion can yield large and lasting changes in attitudes.
Last year, there was a big scandal in political science when a much-publicized paper was retracted on suspicion of fraud. The paper, “When contact changes minds: An experiment on transmission of support for gay equality,” by Michael LaCour and Donald Green, reported on an experiment that purported to show that a brief doorstep conversation with a political canvasser could cause big changes in attitudes toward same-sex marriage. That paper received major and unskeptical media coverage, including a segment on the radio show “This American Life.” It was a big deal, because social science’s understanding had been that political persuasion is difficult.
The scandal came because the study was faked: The data had suspicious patterns that first author LaCour could not explain, and co-author Green retracted the paper. LaCour also falsified claims about the funding and organization of the study.
In the meantime, though, David Broockman and Joshua Kalla, two political scientists who were involved in uncovering the original fraud, conducted their own follow-up study. It was just published in Science, the same journal that published, then retracted, the LaCour and Green paper.
Here’s what Broockman and Kalla found in their field experiment:
A single approximately 10-minute conversation encouraging actively taking the perspective of others can markedly reduce prejudice for at least 3 months. We illustrate this potential with a door-to-door canvassing intervention in South Florida targeting antitransgender prejudice. … 56 canvassers went door to door encouraging active perspective-taking with 501 voters at voters’ doorsteps. A randomized trial found that these conversations substantially reduced transphobia. … These effects persisted for 3 months, and both transgender and nontransgender canvassers were effective. The intervention also increased support for a nondiscrimination law, even after exposing voters to counterarguments.
This new paper looks reasonable to me, and it’s also helpful that they follow good research practices (for example, Broockman provides replication data for most of his research projects). So, yes, it looks like an open-hearted conversation really can change minds. At least in some circumstances.
Also helpful is Betsy Levy Paluck’s thoughtful overview article that appears in the same issue of Science, where she writes:
What do social scientists know about reducing prejudice in the world? In short, very little. Of the hundreds of studies on prejudice reduction conducted in recent decades, only ~11% test the causal effect of interventions conducted in the real world. Far fewer address prejudice among adults or measure the long-term effects of those interventions. … As the authors acknowledge, these strong results in the wake of a brief intervention might seem surprising. But readers may find it even more surprising that so few previous field studies have tested the causal effect of any type of intervention, aimed at any type of prejudice. … Broockman and Kalla’s results thus do not represent a new challenge to an established field: They stand alone as a rigorous test of this type of prejudice reduction intervention.
In particular, Paluck’s article serves as a bit of a rebuttal to that “This American Life” segment, which was called “The Incredible Rarity of Changing Your Mind,” where host Ira Glass said:
There’s this thing called the backfire effect. It’s been documented in all kinds of studies. It shows that when we’re confronted with evidence disapproving what we believe, generally we just dig in and we believe it more. And the rare times that people do change, it’s slow.
But maybe there is no “backfire effect,” maybe that’s just one more bit of incorrect folk wisdom from the psychology literature. Or, at least, such a backfire effect did not seem to apply to Broockman and Kalla’s canvassers who were so effective in persuading people to support transgender rights. At the very least, this suggests a domain-specificity of persuasion and backfire effects.















