From a rational perspective, joining a protest rally is like voting—a complete waste of time. The odds that your voice or your protest sign will make a difference are no better than the odds that your vote will change an election. And yet, people do join protests and people do vote. They do these things not to advance their rational self-interest, but to express moral passions and moral identities.

In Lower Manhattan's Zuccotti Park, home base of the Occupy Wall Street movement, a noisy, festive crowd of hundreds was doing just that when I stopped by on October 8. In an attempt to make sense of the goals and motivations of the protesters there, I brought along a small camera, and Moral Foundations Theory—a theory I developed with Jesse Graham, Ravi Iyer, and Sena Koleva (all at the University of Southern California), Pete Ditto (University of California at Irvine), and Craig Joseph (who was then at the University of Chicago).

This theory, which is based on ideas from the anthropologist Richard Shweder, outlines six clusters of moral concerns—care/harm, fairness/cheating, liberty/oppression, loyalty/betrayal, authority/subversion, and sanctity/degradation—upon which, we argue, all political cultures and movements base their moral appeals.

You can think about the foundations as being like the taste receptors on the tongue: sweet, sour, salty, bitter, and savory. Each political culture, like each culinary culture, creates its own unique cuisine using some combination of these tastes, including elements that lack immediate appeal on their own, such as bitterness. Similarly each political movement bases its claims on a particular configuration of moral foundations. It would be awfully hard to rally people to your cause without making any reference to harm, fairness, liberty, loyalty, authority, or sanctity.

My colleagues and I found that political liberals tend to rely primarily on the moral foundation of care/harm, followed by fairness/cheating and liberty/oppression. They're very concerned about victims of oppression, but they rarely make moral appeals based on loyalty/betrayal, authority/subversion, or sanctity/degradation. Social conservatives, in contrast, use all six foundations. They are less concerned than liberals about harm, but much more concerned about the moral foundations that bind groups and nations together, i.e., loyalty (patriotism), authority (law and order, traditional families), and sanctity (the Bible, God, the flag as a sacred object). Libertarians, true to their name, value liberty more than anyone else, and they value it far more than any other foundation. (You can read our complete research findings at www.MoralFoundations.org and you can take our surveys at www.YourMorals.org.)

So what's the mix of moral foundations at Occupy Wall Street (OWS)? In my visit to Zuccotti Park, it was clear that the main moral foundation of OWS is fairness, followed by care and liberty. Loyalty, authority, and sanctity, by contrast, are very little in evidence.

Fairness/cheating

The psychological meaning of fairness is proportionality. Human beings have been engaging in cooperative enterprises for hundreds of thousands of years, and we're now vigilant for signs that anyone is taking out more than they're putting in. We really hate cheaters, slackers, and exploiters. By far the most common message I saw at OWS was that the rich ("the 1 percent") got rich by taking without giving. They cheated and exploited their way to the top. As if that wasn't bad enough, we the taxpayers then had to bail them out after they crashed the economy, and so now they really owe us for saving their necks. It's high time that they started giving back, paying what they owe.

As a point of comparison, a similar look at signs found at the Tea Party rallies (based on a systematic study done by Reason Foundation Polling Director Emily Ekins) suggests that protesters there are also chiefly concerned with fairness. The key to understanding Tea Partiers' morality, though, is that they want to restore the law of karma. They want laziness and cheating to be punished, and they see liberalism and liberal government as an assault on that project. The liberal fairness of OWS diverges from conservative and libertarian fairness in that liberals often think that equality of outcomes is evidence of fairness.

When everyone's contribution is the same, then the proportional outcome is equality. But in a free market system, where some work harder or are more talented or lucky, it will always be the case that some people make a greater contribution than others, and therefore end up taking home a larger share of the pie. Fairness as proportionality guarantees that outcomes will not be equal. This, I believe, is one of the main reasons why modern leftists (but not classical liberals) are often hostile to capitalism itself, as were some at the OWS protest.

Another unique feature of liberal fairness is that it is often blended with concerns about care for the downtrodden and oppressed, and this brings us to the next foundation:

Care/harm

The second-most common moral foundation on display at OWS was care. My colleagues and I find that liberals score higher than conservatives and libertarians on all measures of compassion and empathy. Liberals are more "soft hearted," and this was evident in many signs:

Liberty/oppression

The moral foundation of liberty was barely evident at OWS in the use of positive terms such as "liberty" and "freedom," though they have have renamed Zuccotti Square "Liberty Square." Occupy Wall Street is not a rally to "get government off our backs," it's a rally to get government to increase regulation of Wall Street and big business. The only sign of direct appeals to liberty that I saw in my visit was this ironic use of a favored Tea Party slogan to protect and care for vulnerable flowers:

Instead, there was a strong emphasis at OWS on the evils of the opposite of liberty, namely oppression. There was a pervasive sense (or hope) that the masses of the weak and downtrodden (the 99 percent) were beginning to unite to throw off the yoke of oppressors (the 1 percent).

This is a process that the anthropologist Chris Boehm has observed in egalitarian societies. When one man tries to act like a leader or overlord, the other men unite into a "reverse dominance hierarchy" to take him down, as illustrated on this protester's sweatshirt showing the unified 99 percent about to crush the 1 percent:

Loyalty/betrayal

The remaining three foundations, which tend to be used more by conservatives than by liberals, were not much in evidence. There were a few American flags scattered about, but the only direct expression of patriotism that I saw was this rather ambivalent sign, which would have not been very welcome at a Tea Party rally:

There were frequent invocations of solidarity, but this is different from the team-vs.-team tribalism of the loyalty foundation. Rather, liberal solidarity aims to erase boundaries between people and groups, to create harmony, not competition. Compared to conservatives, liberals tend to be universalists, internationalists:

Of course, this solidarity is pursued as an effort to unite "the 99 percent" against "the 1 percent"; OWS protesters are perfectly capable of drawing lines between people. Nonetheless, the psychological dynamic here is exactly what Boehm described as a reaction to oppression by an alpha male. It is very different from the dynamic that emerges from intergroup competition (think of gang warfare, or the most extreme sports rivalries) e.g., distinctive symbols, clothing, and heroes, plus an intense focus on expelling outsiders and punishing traitors to the group. None of that was in evidence at OWS.

Authority/subversion

Liberals tend to be wary of authority. I saw no signs suggesting respect for authority, order, or tradition.

Sanctity/degradation

The moral foundation of sanctity is based on the psychology of disgust and spirituality. It's the idea that there's a vertical dimension from God at the top and animalistic carnality at the bottom. When conservative Christians condemn drug use and wanton sexuality, when they say that the body is a temple and life begins at conception, these appeals rest on the psychology of sanctity. Liberals tend to make less use of sanctity; they tend toward materialism (not in the sense of "consumerism" but in the philosophical sense of saying that nothing is divine, nothing is off-limits to human ingenuity and intervention). This cryptic sign would never be seen at a right-wing rally:

However, there was one clear invocation of sanctity and sacredness, a sign declaring a spot to be a "community sacred space":

In short, the moral foundations of OWS are consistent with the moral foundations of the left more generally: fairness, care, and concerns about oppression. The difference is that fairness is cranked up from the second position in which we normally find it (behind care) to the number one motivation. This makes sense given that the protests are a response to the perceived cheating, law-breaking, and greed of the major financial firms.

Many pundits have commented on the fact that OWS has no specific list of demands, but the protesters' basic message is quite clear: Rein in the influence of big business, which has cheated and manipulated its way to great wealth (in part by buying legislation) while leaving a trail of oppressed and impoverished victims in its wake.

Will this message catch on with the rest of the country, much of which also values the loyalty, authority, and sanctity foundations? If OWS engages in acts of violence, flag desecration, destruction of private property, or anything else that makes them seem subversive or anti-American, then I think most Americans will quickly reject them. Furthermore, if the protesters continue to focus on the gross inequality of outcomes in America, they will get nowhere. There is no equality foundation. Fairness means proportionality, and if Americans generally think that the rich got rich by working harder or by providing goods and services that were valued in a free market, then they won't be angry, and they won't support redistributionist policies. But if the OWS protesters can better articulate their case that the "1 percent" got its riches by cheating, rather than by providing something valuable, or that the 1 percent abuses its power and oppresses the 99 percent, then Occupy Wall Street will find itself standing on a very secure pair of moral foundations.

Jonathan Haidt is a professor of psychology at the University of Virginia, and is a visiting professor of business ethics at the NYU-Stern School of Business.