Are you someone who struggles to understand why people behave the way they do in politics? Perhaps you've been confused by all the fervor against gay marriage. Or maybe you're taken aback by the strong emotions waged against government-sponsored health care.

To understand political behaviors like these, you'll need to become familiar with the psychology of disgust. Researchers have learned a lot about it in recent years, such as:

• Disgust – like all emotions – is biological and can be explained through the workings of the brain;
• Disgust is the physiological foundation for moral notions of purity and sacrilege;
• Disgust, once felt, creates a persistent association that is very difficult to get rid of;
• Disgust is a powerful motivator of behavior, helping deter us away from perceived threats to our health.

So what does this have to do with politics? In a word, everything.

Politics on the Brain

If you've read the work of George Lakoff, Drew Westen, or Jonathan Haidt you'll know that there's quite a buzz in the academic world around recent discoveries into the political mind. Distinct moral worldviews have been systematically explored. Profound biases have been demonstrated in the ways brains process information depending on whether the person identifies as a liberal or conservative. And distinct moral sensitivities have been found across different political groups that correspond with key social emotions.

As I argued in a recent article, the understandings coming out of this research are absolutely critical for cultivating a political culture that is conducive to participatory democracy. This is especially true for the emotion of disgust.

Emotions are physical. They are very complex processes that occur in our brains, each serving vital purposes for our survival. Disgust in particular is the result of our bodily need to avoid toxic substances, especially rotten and poisonous foods. Thus it is most closely associated with bodily functions having to do with digestion.

At its most basic level, disgust can be thought of as the unpleasantness that arises when the body is contaminated. The brain has sensors to recognize when the body has been contaminated and it uses specific chemical markers to remember events that may have lead to the unpleasantness that followed.

The Feeling of Morality

For a long time, the study of morality was relegated to the halls of our philosophy and political science departments. This has changed in a serious way. There are now a wide variety of scientific research programs dedicated to understanding the physical, biological, and evolutionary foundations of morality. When Sam Harris took up this topic a few weeks ago, he barely scratched the surface of what is known today.

Research centers include the International Institute on Cognition and Culture at the London School of Economics, the Greater Good Science Center in Berkeley, the Institute on Cognition and Culture in Belfast, and the Center for Human Evolution, Cognition, and Culture in Vancouver, just to name a few.

One of the major discoveries so far is that morality is grounded in our bodily experience. We literally feel right and wrong in our bodies. Disgust is a physical experience that applies to notions of moral purity, moral health, and our judgments about how to handle situations like incest, cannibalism, and rape. For each of these emotionally potent topics, the strength of our feelings corresponds directly with our sentiments about how they should be handled in society.

Research tailored to the study of moral purity and the emotion of disgust was conducted by Paul Rozin, Jonathan Haidt, and Rick McCauley. (A copy of their seminal article can be requested here.) They showed that the physical experience of disgust provides the bodily foundation for the moral concept of purity. Put succinctly, when you experience the feeling of moral disgust – via the tainting of something you hold sacred and pure – it is produced by the same neural and chemical process that arise after biting into a moldy piece of bread or some rotten fruit.

Avoiding the Rotten Apple

The experience of disgust is very persistent. Once we associate those negative feelings with an idea (like 'liberalism' or 'Obama the Muslim') it is very hard to shake off. The explanation for this comes from the field of evolutionary psychology, which explores the evolutionary origins of human thought and behavior. Animals that remember the foods that make them sick are more likely to survive and reproduce. So those who have a long memory of disgust are better adapted for survival.

Applied to politics, this phenomenon implies that once a political idea becomes a rotten apple it will remain a rotten apple. Disgust tends to stick around. This is why so much time, effort, and money is dedicated to painting the opposition with negative feelings. If a disgust response can be evoked, it will tend to stay around.

Think about the ramifications for gay marriage. If children are taught that homosexuality is disgusting, they will want to stay far away from it. As their moral sentiments develop, they will begin to see homosexuality as a contaminant in society. When thinking about the sacred institution of marriage, they will feel the threat of this impurity to something they want to keep clean. It's pretty easy to mobilize them against this threat because the feeling is long-lasting and easy to activate with a political sound bite.

There are two lessons to learn from this. First, if you want someone to support your idea (like the notion that addressing global warming might be a sensible thing to do), don't let it get associated with disgust (such as how people feel about the elitism of scientists - be it real or imagined). Second, if you want someone to oppose an idea, just riddle it with associations to the profane and impure. Do so with references to basic bodily functions and you'll be particularly effective.

These tactics have long been used in politics to the detriment of civil society.

Mobilizing an Opposition

How do different political communities respond to the phrase "Rush Limbaugh?" For progressives, a strong feeling of disgust will arise at the mere mention of his name. He is associated with hate speech, xenophobia, and violent rhetoric that violates our civil sentiments. Yet, conservatives who have been primed by repeated messages on Limbaugh's show will experience a powerful sense of solidarity with anyone opposed to the revolting 'liberal elite.'

Same stimulus, different response. Yet both are examples of disgust influencing political behavior.

Disgust is a social glue that binds people together against a common threat. Once opposed to a person, policy or idea at this basic level, it is very easy to mobilize around any effort to remove the threat. This is a foundational theme in politics. So if you ever hear an assertion that people are rational actors who reason their way to conclusions, remember this powerful ability of disgust to stand in for reason and compel action.

Why Am I Telling You All of This?

Knowledge about the psychology of disgust can be detrimental to democracy if held in the hands of a scrupulous elite. When political strategists learn about the power it can have to influence behavior, they may play their hand at being gods and use it to manipulate the citizenry. This begs the question why I'm publishing these findings to the world.

My answer is that I firmly believe in the democratization of knowledge. The more people know about how the political mind actually works, the more likely it will be that tactics that exploit disgust are recognized and called out for being unethical. This extends beyond politics proper. I like to imagine a world where marketing techniques are based on fundamental trust between people that grows out of honest communication intended to resonate authentically with an audience. To get to this world, a lot of people are going to have to learn about the workings of the political mind. Eventually, it will need to be taught in our schools as part of the standard curriculum for civic life.

For too long, insights like these have been held in secret to be used for elite control of the populace. I hope to do my part by sharing knowledge about the political mind with the world so that we can work together to build safeguards into the fabric of our society and restore faith in our democratic institutions. 

This work by Truthout is licensed under a Creative Commons Attribution-Noncommercial 3.0 United States License.