Consider the classic hypothetical scenario: Your house is on fire and you can take only three things with you before the entire structure becomes engulfed in flames. What would you take? Laptops and external hard drives aside, people’s responses to this question differ wildly. This diversity results from people’s flexibility in ascribing unique value to objects ranging from a hand-scrawled note from a loved one to a threadbare t-shirt that others might consider worthless.

The critical quality that leads people to treat rookie cards like rosaries is that of the sacred, whereby an object becomes worthy of boundless reverence, commitment, and protection. As diverse as people are in ascribing sacred status to possessions, they are equally varied in which values they consider sacred, a diversity that can breed substantial conflict. The abortion debate, for example, often presents a divide between those who consider woman’s “right to choose” sacred versus those who consider a fetus’ “right to life” sacred.

A recent study in the journal for Judgment and Decision Making assessed how the Iranian nuclear defense program has become a sacred value and how this affects negotiation over Iranian disarmament, an issue of growing global concern. Just last month Iran defied the United Nations in beginning to enrich its uranium supply to bolster its nuclear program. The recent study on this topic by Morteza Dehghani and colleagues, offers two key insights. It demonstrates how a relatively recent issue, one that—unlike abortion—lacks any longstanding historical or religious significance, can become sacred. And it suggests, surprisingly, that offering material incentives in exchange for sacred values may backfire badly. The work is a reminder that sacred values are tremendously influential in disputes both international and interpersonal, but that our negotiating instincts can lead us away from common ground.

What truly distinguishes sacred values from secular ones is how people behave when asked to compromise them. When people are asked to trade their sacred values for values considered to be secular—what psychologist Philip Tetlock refers to as a “taboo tradeoff”—they exhibit moral outrage, express anger and disgust, become increasingly inflexible in negotiations, and display an insensitivity to a strict cost-benefit analysis of the exchange. What’s more, when people receive monetary offers for relinquishing a sacred value, they display a particularly striking irrationality. Not only are people unwilling to compromise sacred values for money—contrary to classic economic theory’s assumption that financial incentives motivate behavior—but the inclusion of money in an offer produces a backfire effect such that people become even less likely to give up their sacred values compared to when an offer does not include money. People consider trading sacred values for money so morally reprehensible that they recoil at such proposals…