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Was Trump’s Speech Good Only Because of the Contrast Effect?

A common illusion could explain why people responded positively to the speech.

Wikimedia Commons, Michael Vaden
Source: Wikimedia Commons, Michael Vaden

Tuesday night, President Trump addressed the joint houses of Congress to an overwhelmingly favorable public response. According to a CNN poll, 78 percent of viewers rated the speech positively, an impressively high score given that Trump's overall job approval rating has been among the lowest in history for a newly-elected president, hovering in the forties.

This is a particularly odd mismatch if one considers that most analysts believe he didn't say anything new. His plans remained largely unchanged. According to The Washington Post and The Boston Globe, the talk even contained the same inaccuracies that Trump has been known for during his first 40 days in office.

So, why was Trump's speech so well received?

A quick tour of media reports may help answer that question. Senate Majority Leader Mitch McConnell declared, "Donald Trump did indeed become presidential tonight." CNN commentator Van Jones likewise stated, "He became President of the United States in that moment, period." Perhaps one blogger summed it up best: "His policy proposals were mostly sound. His delivery was quite good. He didn't angrily seek to pick fights. In short, he appeared presidential."

But, almost by definition, most presidents appear "presidential" during their speeches. Just a year ago, this would have seemed like the bare minimum criterion a presidential speech must meet to be considered adequate, let alone excellent. So what's different now? 

One of the biggest differences lies in the fact that many people felt Trump had not acted presidential up until that moment. This created the perfect conditions for something that psychologists call "the contrast effect."

Technically, the contrast effect occurs when a viewer perceives a stimulus as either enhanced or diminished because he or she had previously been exposed to a contrasting stimulus. The same cheap chocolate that tastes only adequate following a sumptuous meal may taste incredibly delicious if you’ve been forced to eat nothing but stinky cheese for three days.

Wikimedia Commons, public domain
Source: Wikimedia Commons, public domain

Well understood by psychologists for decades, the contrast effect is at the root of many perceptual illusions. Take a look at the image of the gray boxes on this page. If you’re like most people, the small inner rectangle in the top half of the picture appears to be slightly lighter than the one in the bottom half, even though both are exactly the same shade. The darker gray background in the top half of the image provides a contrast, creating the illusion that the small box contained within it is brighter than it actually is.

The contrast effect works for preferences, as well. In a now classic experiment, participants were given a brief paragraph describing a hypothetical person (coincidentally named “Donald”) in relatively neutral terms and were asked to give their opinion about that person. Just before reading the paragraph, however, they were asked to a do a quick crossword puzzle in which they circled the names of various famous people. When the puzzle contained names like “Adolph Hitler,” participants subsequently rated the hypothetical person described in the paragraph as more positive than when the puzzle contained names like “Pope John Paul.” Thinking about Hitler lowers our threshold for judging a person as good. It sets an expectation that nearly anyone can beat, amplifying how friendly they seem.

Just as in the experiment, when Trump took to the podium Tuesday night, the world had a set of expectations based on his previous un-presidential behavior. In comparison to those expectations, Trump's performance surprised us. The gap between our previous experience and his current performance set the stage for the contrast effect. The chocolate was a welcome break from the stinky cheese.

Of course, this begs the question: Was the chocolate actually any good? If we could somehow turn off that part of our brains responsible for the contrast effect, preventing our past experience from influencing our current judgments, how would we rate Trump's speech? Did it actually warrant such a high public opinion?

Perhaps only history will tell.