Psychology
The Influence of Political Advertising on Candidate Evaluation and Turnout
Quick fact
Meta-analyses of field experiments show that campaign ads have a statistically significant but small effect on candidate evaluation (e.g., shifting favorability by a few percentage points), while their effect on voter turnout is negligible on average—yet negative ads can sometimes increase turnout by sparking outrage.
Why this is interesting
Ever watched a campaign ad and felt a sudden surge of hope or anger—and wondered if it actually changed your vote or even whether you'd bother showing up? Political advertising is designed to do both, but the science behind its effects reveals a surprising twist.
Read the full explanation
Understanding The Influence of Political Advertising on Candidate Evaluation and Turnout
Think of political advertising like a vivid weather forecast during a storm: it doesn't change the storm itself, but it changes how people prepare for it. When a voter sees an ad, they gain new information about the candidate—a stance, a scandal, an image. This information can be processed in two ways: quickly, using heuristics like party affiliation or the candidate's likability, or more carefully, if the ad resonates with the voter's values. The evaluation happens as the voter updates their mental scorecard of the candidate. Similarly, the decision to vote is influenced by the ad's emotional tone: an ad that makes a voter feel hopeful may increase their sense of civic duty, while an ad that breeds cynicism could make them feel their vote doesn't matter. Crucially, these effects are not automatic—they depend on the voter's prior knowledge, partisanship, and the competitive context of the race.
A deeper explanation
The mechanism underlying advertising effects involves two pathways: persuasion via information updating and behavioral activation via emotion. Ads supply cues that voters use to evaluate candidate traits (competence, integrity) and issue positions. Because voters are cognitive misers, they rely on mental shortcuts (heuristics) like party identification or endorsements, which ads can activate. This explains why ads are most persuasive for less informed or less partisan voters. For turnout, the affective intelligence model suggests that emotions like anxiety trigger attention and information-seeking, potentially motivating voters to participate, while enthusiasm reinforces existing choices and boosts mobilization. Conversely, a stream of purely negative ads can lead to political cynicism and demobilization, especially among independents. Field experiments (e.g., by Green, Gerber, and colleagues) show advertising has modest effects on candidate choice (around 2–5%) and near-zero effects on turnout, except when ads are combined with get-out-the-vote efforts or when they highlight high-stakes issues. The key is that turnout is a habitual behavior; ads alone rarely break that habit, but they can tip the balance among those already leaning toward voting. Understanding this mechanism is vital for evaluating campaign finance debates and the health of democratic participation.