CONSIDER the classic hypothetical: Your house is on fire, and you can rescue only three things before the structure is engulfed in flames. What would you take? Laptops and external hard drives aside, people’s responses to this question differ wildly—from a hand-scrawled love note to a valuable coin collection or even a threadbare T-shirt that anyone else would consider worthless.

The tendency to consider commonplace objects worthy of reverence and protection—to treat rookie cards like rosaries—is a universal human experience. Such powerful emotions are not rooted in any specific faith or belief system; nevertheless, they have a spiritual quality—and many psychologists use the term “sacred” to describe objects toward which people proclaim an unbounded or infinite commitment.

If people ascribe sacred status to possessions, then it is no surprise they do the same with their moral stances. And just as a Beatles compilation is the pinnacle of music to one person, whereas to another it is an album from Justin Bieber, people differ in which values they consider sacred—a diversity that can breed substantial conflict. The abortion debate, for example, presents a divide between those who consider a woman’s “right to choose” sacred versus those who hold a fetus’s “right to life” sacred. A few recent studies have examined how people react when their most passionately held values are challenged. And because these values often play out in the political arena, the new psychological insights may help reframe bitter and long-standing international disagreements.

Your Money’s No Good Here

A sacred value is more than just a strongly held belief; it is a moral stance on which the holder will not budge, no matter what the conditions. Psychologists determine who feels certain values are sacred by looking at how people behave when asked to compromise. For instance, psychologist Jeremy Ginges of the New School for Social Research and cognitive anthropologist Scott Atran of the University of Michigan at Ann Arbor asked Indonesian madrassa students if they thought in some extreme circumstances it would be permissible to accept that sharia (Islamic law) would not be the law of the land. The researchers considered students who answered “no” to such questions to hold the belief in sharia sacred. Others may have felt quite strongly that sharia should be upheld, but if they were willing to entertain the idea that in rare cases sharia could be compromised, they did not, by definition, consider the value sacred.

It makes sense that a value rooted in religious belief would be sacred, but people exhibit such boundless commitment to other values as well. Some consider it unthinkable to root against their home team or vote against their political party—they would not do so for any inducement, even a large amount of money. In fact, when people are offered cash to relinquish a sacred value, they tend to display a particularly striking irrationality—they recoil viscerally, even though the proposition is not objectively immoral. Psychologist Philip E. Tetlock of the University of California, Berkeley, refers to these hypothetical exchanges as “taboo trade-offs,” because people react to them with moral outrage; they express anger and disgust and become increasingly inflexible in negotiations.

Reframing the Debate

In 2007 Ginges and his colleagues discovered this backfire effect in studies of the Israeli-Palestinian conflict. They identified Israelis and Palestinians who possessed sacred values regarding key local issues such as who owns the West Bank and other disputed territories—these people viewed compromise as unacceptable under any circumstances. The researchers asked the subjects who held sacred values to respond to several hypothetical bargaining deals over issues central to the Israeli-Palestinian conflict. When the deals included receiving a monetary payout—for instance, billions of dollars in aid from the U.S. in exchange for giving up a disputed territory—both Israelis and Palestinians expressed more outrage and became more supportive of violence as a form of opposition. Opposition decreased, however, when the scenario included the other side compromising a sacred value of its own, such as Israelis formally renouncing their right to the West Bank or Palestinians formally recognizing Israel as a state.

Deep historical and religious traditions may be at the root of many inviolable values, but an intriguing new study suggests that even relatively recent issues can quickly become sacred to a population. Psychologist Morteza Dehghani of Northwestern University and his colleagues asked 75 Iranians how they would feel about the possibility of Iran giving up its nuclear program, giving them four response options on disarmament ranging from “definitely needs to happen” to “shouldn’t be done no matter how great the benefits are.” Those who chose the latter were classified as treating the matter of Iran’s nuclear program as a sacred value.

After giving their opinions on Iran’s nuclear program, all participants were asked to consider one of two deals for Iranian disarmament. Half the participants read about a deal in which the U.S. would reduce military aid to Israel in exchange for Iran giving up its military program. The other half read about a deal in which the U.S. would reduce aid to Israel and would also pay Iran $40 billion. After considering these proposals, participants predicted how much the Iranian people would support the agreement and how much anger they would feel toward the deal. In line with Ginges’s studies, those who considered the nuclear program a sacred value expressed less support and more anger when the deal included money—even though that arrangement was objectively more beneficial to Iran. The other study subjects were more likely to appreciate the offer of aid.

The implication for international negotiation is clear: when a value becomes sacred, the rules change—offering money hurts instead of helps. Conflicts may be best resolved when both sides consider compromising something they hold dear. Choosing the right words may help, too—Tetlock’s studies have shown that emphasizing the dire, necessary nature of a trade-off can facilitate conflict resolution. For example, people are more willing to sell their body organs for medical transplants when told it is the only way to prevent deaths. Initially, selling organs feels like a violation, but that gut reaction changes when alternative sacred values are invoked: altruism and saving lives. Whatever the subject of discussion may be, when sacred values are on the negotiating table, it pays to understand the psychology of the taboo trade-off.