In poll after poll, Americans say they don’t like negative campaigning. Yet in the final week of the Florida primary, more than 90% of the ads broadcast were attack ads. That’s not likely to change in the run-up to Super Tuesday.

So why do candidates rely so heavily on a kind of advertising voters say they abhor?

Because it works. To understand why, you have to consider what we know about how emotions work — and the different ways our conscious and unconscious minds and brains process “negativity” during elections.

In 2008, my colleague Joel Weinberger and I tested voters’ conscious and unconscious responses to two ads. The first was an anti-Barack Obama ad of Hillary Rodham Clinton’s. “It’s 3 a.m., and your children are safe and asleep,” it began, “but there’s a phone in the White House and it’s ringing.” It then went on to suggest that Clinton, because of her seasoning in national politics, was far better qualified to answer that phone than the less-experienced Obama.


The second was an anti-John McCain ad put out by the Campaign to Defend America. It was designed to suggest that a vote for McCain was a vote for four more years ofGeorge W. Bush policies. The ad juxtaposed the policies promoted by the two men and interchanged their heads, concluding that the Republican nominee was “McSame as Bush.”

The voters we surveyed claimed to despise both ads, describing them in focus groups as “pandering.” They insisted the ads would backfire with them. But using a well-established method for assessing which words the commercials activated unconsciously, we discovered that although voters consciously disliked both commercials, the ads were nevertheless highly effective. Both “stuck,” triggering negative associations with Obama and McCain in the minds of most viewers, including those who thought they were unaffected. When viewing the face of Obama, the words most strongly activated by the “3 a.m.” ad were “weak,” “lightweight,” “terrorist” and “Muslim.” The word that stuck unconsciously after the “McSame” ad was “Bush.”

Viewers may have rejected the ads consciously, but that doesn’t mean they weren’t unconsciously affected.

Our conscious reactions reflect our conscious values. In the case of campaigns, for most people, those values include a belief that people should run on their merits and stop tearing each other down. But unconsciously, our brains are highly reactive to threat — especially when, as in the case of an ad, the threat isn’t immediately countered or refuted. A well-crafted positive ad can “stick” too, but there’s nothing like a sinister portrayal of a greedy, self-centered villain, replete with grainy images and menacing music, to stir up our unconscious minds.


Attack ads have pros and cons in a primary. On one hand, they can do great damage to a candidate who may ultimately be the party’s choice. Romney is the target of both Newt Gingrich and Rick Santorum now, but if the former Massachusetts governor ultimately gets the Republican nomination, the party will want voters to forget all the primary attacks. And his own attack ads in Florida against Gingrich — which were highly effective — created negative associations to him too. The plus side to these kinds of early attacks is that they come far enough in advance of the election that they may feel like old news come November. Moreover, they give candidates a preview of attacks that will likely come from the other party in the general election and allow them to prepare responses in advance. Gingrich’s attacks in Florida, for example, forced Romney to find a better answer to charges that he is a “vulture capitalist” who earned his money by putting people out of work.

It’s ironic that so much attention is now being focused on the impact of Gingrich’s attack ads, which seem to have left the unlikely Santorum as the latest beneficiary of Republican anti-Romney sentiments. In Iowa, Gingrich was leading in the polls until his rivals began hitting him with one attack after another. He chose not to respond, taking voters at their word that they wanted a positive campaign. That was a rookie error, particularly striking for a veteran politician who had made his way to the top of the GOP leader board with his razor-sharp debate responses, and who had spent a career as a professional gadfly, never shy to take a shot at anyone, even Ronald Reagan.

Gingrich’s refusal to answer the attacks may have reflected the hubris that has so often been his undoing, or it may have stemmed from an admonition by his pollsters that a tit-for-tat campaign would drive up his already sky-high negatives with swing voters. But whatever the reasoning, it was wrongheaded if he wanted to win — and the once front-runner found himself a distant third in the Iowa caucuses.

Every political strategist knows that there are four stories you have to control if you want to win an election: the story you’re telling about yourself, the story your opponent is telling about himself, the story your opponent is telling about you, and the story you’re telling about your opponent. Gingrich lost Iowa because he was talking only about himself — ignoring the unflattering picture the other candidates were painting of him and failing to speak to the legitimate weaknesses of his rivals.


The reason it’s so crucial for politicians to activate both negative and positive emotions is that they are not, as our intuition would suggest, just opposites. Emotions such as anxiety, fear and disgust involve very different neural circuits than, say, happiness or enthusiasm. A candidate’s job is to get all those neural circuits firing, both the ones that draw voters in and the ones that push them away from other candidates.

That doesn’t require making things up about your adversaries. You don’t have to bend the truth too far to paint a worrisome picture of any of the candidates this year — or to present an image that’s positive (at least with some creative air-brushing).

But in hard times with flawed candidates, expect a lot of negative campaign ads between now and November.

Drew Westen is a professor of psychology and psychiatry at Emory University and the author of “The Political Brain: The Role of Emotion in Deciding the Fate of the Nation”