Long before Barack Obama chose “Yes We Can” as his 2008 campaign slogan, Republicans had been dubbed the Party of No. The label is popular among liberals as an insult for the GOP, but it’s also been embraced by conservatives as a proud self-description: for some on the right, the Party of No conjures the adults in the room saving future generations from an orgiastic spending spree, in the spirit of William F. Buckley’s proclamation that conservatism “stands athwart history, yelling Stop.” These conflicting views were on display in the recent debt ceiling negotiations, with liberals frustrated by Republican obstructions, and conservative Tea Party members seeing it as their duty to say No to another debt ceiling increase.

Whether intended as a slur or a badge of honor, the Party of No label stems from specific policy preferences, mainly the conservative tendency to vote “no” on non-security domestic spending and tax proposals. At first blush, policy stalemates might seem simple differences of opinion on how to run the country.  But a growing body of evidence is showing that partisan rancor goes far beyond the budget and policy fare of Sunday morning talk shows.  As divisions between Red States and Blue States have grown (or at least acquired greater iconographic heft), so has interest in understanding the temperamental and attitudinal foundations of political ideology. An explosion of research over the last decade is revealing the psychological underpinnings of ideological differences, unearthing the subterranean meanings of the Party of No.

That Democrats and Republicans differ on matters from foreign policy to gay marriage is well established, but how do individuals arrive at such diametrically opposed worldviews? Researchers at Virginia Commonwealth University recently published evidence that even nonpolitical attitudes are formed differently in liberals and conservatives.

In two studies, students were presented with a conditioning task involving positive or negative images (like puppies and garbage) flashed before pictures of Chinese characters. The characters were totally new and value-neutral for these non-Chinese speaking students. Some characters always followed the cheery puppies and rainbows, while some always appeared after the aversive sewage and spiders. Another set came after a neutral gray square.

After a few viewing cycles, the students simply rated how much they liked or disliked each of the Chinese characters. (They had been told they were participating in a language and memory experiment to avoid muddying the data with political assumptions or overtones.) Both studies showed that the negative images had a stronger effect than positive images for everyone, supporting the robust psychological finding that negatives make a stronger impression than positives (i.e. the snarky evaluations you remember long after the glowing ones have faded).  After the brief viewing, Chinese characters that had appeared after negative images were more disliked than the other Chinese characters, even though participants had no prior experience with them.

Most strikingly, both studies showed that this negativity dominance was especially true for conservative students. In other words, those on the political right showed more of a “bad is stronger than good” bias than those on the left. Surprisingly, the political difference wasn’t to be found in the negative images, which had a strong effect on everyone across the board. If you can wrap your mind around psych study jujitsu for a moment: the differences stemmed from participants’ responses to the positive images, which carried more weight with liberal students. For example, if viewing two hypothetical television ads—one featuring an impoverished village in shambles after a failed food distribution program, and one showing clean, happy children after a successful well installation—liberals may be more likely to be convinced of the potential success of future aid programs.

This finding fits with previous studies showing conservatives (relative to liberals) to be more responsive to threats, more resistant to change, and more likely to see the world as a dangerous place – all of which involve some form of negative attitudes, be they about the past, present, or future. But the new studies stand out for two reasons. First, the attitudes being formed were not about political figures, or the role of government, or moral values, or anything else one could conceivably expect liberals and conservatives to argue about; they were about Chinese characters flashed on a computer screen with pictures of puppies or garbage.

Second, the political differences seemed to be inherent not in any consciously endorsed attitudes, but in the unconscious processes of attitude formation itself. In fact, in the second study people also directly rated how much they liked the pictures of puppies and garbage, and there were no political differences in these ratings (even though the pictures were having different unconscious effects). Thus the paper is one more indication that liberals and conservatives differ in ways unrelated to politics – and in ways they may not even be aware of.

Like much research on ideological differences, these findings are likely to inspire as much controversy as wonder, with liberals hailing the discovery of a new conservative bias, and conservatives dismissing the research itself as biased. But like many of the findings about ideology, this finding can be spun different ways: if you want to flatter the left, you can say it shows them as less biased, less cynical, and more open to a positive worldview. If you want to flatter the right, you can say this shows conservatives as more cautious, less pie-in-the-sky, and even more sensible (if you think negative information should have more of an impact). Like the Party of No label, the Psychology of No could be an insult or a compliment, depending on which side of the political spectrum you’re on.

Are you a scientist who specializes in neuroscience, cognitive science, or psychology? And have you read a recent peer-reviewed paper that you would like to write about? Please send suggestions to Mind Matters editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe. He can be reached at garethideas AT gmail.com or Twitter @garethideas.