Post developed by Katie Brown and Kristyn L. Karl.

It’s election time again. And elections bring advertising assaults by Internet, radio, and TV. In Michigan and Iowa, there is one political TV ad every two minutes. But what effect does this have on potential voters?

Center for Political Studies (CPS) affiliate and Ph.D. Candidate in Political Science at the University of Michigan Kristyn L. Karl investigated this question. Where previous research in this area uses self-reported measures of emotional response, Karl tackled the issue with a randomized experiment capturing a direct measure of physiological arousal – skin conductance. She was interested in the impact of emotional arousal from political ads on citizens’ intention to participate in politics.

Sample Skin Conductance Output

Sample Skin Conductance Output

For the study, Karl brought participants into the lab and measured their skin conductance while watching a political advertisement. The ad was fictitious and created in a way that gave Karl control over the message, images, music, and structure. Karl designed four ads: a positive Democratic or Republican ad, and attack ads on Democrats or Republicans. Participants randomly watched one of the four ads while their physiological arousal was captured; after the ad, they reported their current emotions and their willingness to participate with regard to 1) signing a petition, 2) initiating a conversation on a political topic, and 3) attending a meeting, rally, or demonstration.

Karl finds some key differences between political novices and more experienced participants. For political novices, both physiological arousal and self-reported negative emotion positively predicted participation in politics. Among political experts, however, the connection between arousal, self-reported emotion, and intended participation is more muted. Specifically, while the trend is still positive, the effect fails to reach statistical significance.

The Marginal Effect of Physiological Arousal on Political Participation by Political Sophistication

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Karl turns to theory to explain the limited effect of arousal on intention to participate among experts. Experts have a well-developed cognitive network about politics which, for better or worse, allows them to more easily interpret and condition their emotional responses to political stimuli. Political novices do not have this expansive network and so react in a more instinctual way. The model below captures this:

flowchart

This experiment highlights the importance of using alternative measures of emotional arousal as a complementary tool to self-reported measures. Moreover, it draws attention to the question of for whom political ads are motivating and how do they work.