Persuasion research is usually not in the spotlight. But it’s easy to see why this study made news. A “meta analysis” summarizing 49 research studies concluded that most messages in political campaigns have little or no impact on voters. End of story.
It’s my vocation to understand how and when people change their minds. This requires a sense of both the art and science of engineering consent: a tall order that is never easy. Persuasion analysis is a business that needs humility. Even so, there is no shortage of serious and not so serious attempts to uncover pathways to attitude and behavior change. Interest in this subject feeds off of the central roles that advertising, political campaigns, and social action campaigns play in our culture.
Any study of persuasion effects must yield to the general operating principle in communication that context matters; any conclusion about the effectiveness of persuasion must usually come with a lot of case-specific caveats. Uniformity of effects across forms as different as political canvassing and advertising is not likely. Given that basic assumption, it came as a complete surprise to see a spate of news reports about a recent study by two young political scientists claiming that a large number of field experiments found no or minimal effects for all kinds of campaign activities we take for granted. The media at the center of the research included television advertising, person to person canvassing, phone calls and mail. The “meta analysis” summarizing 49 research studies found little or no impact on voters in any of these forms.
The uniformity of null effects was a shock. In the past, studies have suggested a range of different effects for different media: typically, with an edge going to one-on-one meetings with voters. Those of us studying these things have a general understanding of events like the 2008 Obama campaign, where the effects of internet-energized supporters and effective block-by-block canvassing produced a convincing win. Or so we think. Was that a different time? What has changed? There is no equivocation in the final conclusion of authors Joshua Kalla and David Broockman:
The best estimate for the persuasive effects of campaign contact and advertising--such as mail, phone calls, and canvassing--on Americans' choices in general elections is zero. Our best guess for online and television advertising is also zero. . ."1
To be sure, few persuasion researchers find evidence for widespread effects anywhere. The prevailing view is for only limited effects, typically “post message” percentages of attitude change in the low single digits. Even so, a study that argues against any significant effects seems too bold, too panoramic, and a bit disheartening. It’s somewhat like telling advertisers they are wasting their time and money.
The authors have added some exceptions. If we accept their work, messages do shape responses to ballot initiatives and some primary campaigns. And in an earlier study they noted that activists for transgender and gay rights did reduce prejudice when they were able to meet people at their doorstep.2 Personal stories of travail or unfairness struck home for undecided listeners.
Our soap-opera politics has perhaps wrung out the possibility of an open mind among those who are still paying attention.
But the broad suggestion of a brick wall of “no effects” in campaigns is stark, and raises a number of questions. Are the studies’ measures of attitude and behavior change too crude to detect shifts? Did being a part of a study effect the results? This problem–sometimes called the Hawthorne Effect–arises if subjects know they are subjects, and act accordingly.
Then, too, because all of the messages were focused on political campaigns, we may have reached a point where the persistence of attitudes now is much more common than even a decade ago. Our soap-opera politics has perhaps wrung out the possibility of an open mind within those who are paying attention. In any case, the question of what works remains partly unanswered.
1“The Miminal Persuasive Effects of Campaign Contact in General Elections: Evidence from 49 Field Experiments,” September 25, 2017, American Political Science Review.
2 “Durably Reducing Transphobia: A field Experiment on Door-to-Door Canvassing,” http://science.sciencemag.org/content/352/6282/220.