The psychologists are making an assumption that is difficult to prove. They have to assume that at some point in our lives—probably in our early years—we face, and recoil from, the realization that we will eventually die, and that we then resort to what the psychologists call “worldview defenses.” The authors cite the findings of British psychologist Sylvia Anthony, who found in interviews with mothers and children that children between the ages of eight and twelve do worry about death. I can remember that myself. The psychologists also cite different kinds of neurotic and psychotic mental illnesses, when early fears of death reemerge with a vengeance.

Within a community, society or nation, different worldviews are developed collectively as defenses against this elemental fear of death. They vary from the most literal defense—a worldview that unites church, state and family around the promise of immortality—to the most complex and layered symbolic defenses that involve the promise of wealth, fame or other kinds of status. Young people absorb and adopt these worldview defenses as they grow up. But they still react differently to mortality reminders. How they react is dependent, the psychologists argue, upon their level of self-esteem.

Individuals’ self-esteem flows from their confidence that, in accordance with prevailing worldviews, they are achieving or are equipped to achieve (by intelligence, status, appearance or wealth) literal or symbolic immortality. “Self-esteem,” the psychologists write, “enables each of us to believe we are enduring, significant beings rather than material creatures destined to be obliterated.” And the psychologists have designed experiments to show that a person’s susceptibility to fear of death, and to mounting strong worldview defenses, is determined by the degree to which they feel self-esteem.

In these experiments, the psychologists first devise procedures that will either lower or raise subjects’ self-esteem (for instance, they have them take tests, and then inform them they have scored high or low on an IQ test, or are perfectly fitted or completely unsuited for their chosen careers). They then have them take word-association tests that compare the speed of their response to words that connote death with the speed of their response to words that are either neutral or connote pain. Or they have them complete words like “coff _ _,” which could yield either “coffee” or “coffin.” These tests have confirmed that lowering self-esteem allows death-related thoughts to predominate, while raising self-esteem wards them off.

THE PSCYHOLOGISTS’ theory has very broad implications for understanding social groups, nations and individuals. It would suggest that people with higher self-esteem are more likely to display tolerance toward people holding beliefs other than their own and that people who feel low self-esteem are more susceptible to racial, national or religious appeals that demonize “the other”—whether they be Jews, African Americans, illegal immigrants, Arabs or Uighurs. In communities whose members suffer from being unable to fulfill the demands of the prevailing worldviews, it is common to find outlaw and gang cultures, which promise alternative paths to symbolic immortality.

This theory offers a plausible alternative to Freud’s explanation for the irrational passions that fuel social violence and wars. In Civilization and Its Discontents, Freud attributes much of violence and war to a death instinct or drive, but the psychologists attribute it to worldview defenses created by the fear of death. While peoples and nations can go to war over scarce resources, they can also go to war over rival belief systems. “Our longing to transcend death inflames violence toward each other,” the psychologists write. Likewise, as Becker had written in The Birth and Death of Meaning, “One culture is always a potential menace to another because it is a living example that life can go on heroically within a value framework totally alien to one’s own.”

It’s hard to demonstrate this, but the psychologists have devised experiments that suggest that mortality reminders can inflame people’s hostility toward views other than their own. Through questionnaires, they divided subjects into liberals and conservatives, and paired each person off with someone whom they were told held views opposed to their own. They were told that the study was about food habits, but that before their partners could sample foods they had to ingest an overly spicy salsa sauce that the subjects would measure out in a cup and give to them. Subjects who did not have mortality reminders gave their partners small doses of the sauce, while those who were reminded of their mortality filled their cups to the brim.

The psychologists’ theory, echoing Becker as well as Rank, also attempts to explain the age-old differentiation between soul or mind and body. The body is a reminder of our mortality. “Our bodies and animality are threatening reminders that we are physical creatures who will die,” the psychologists write. “To manage our terror of death we have to be much more than that...so we transform our bodies into cultural symbols of beauty and power. We hide bodily activities [such as defecation] or turn them into cultural rituals.” The psychologists actually tested these ideas in various experiments—for instance, measuring how far subjects sat from a woman whom they believed was breast-feeding after the subjects had written essays about death.

In his later works, Freud attributed sexual ambivalence to a fusion of the sexual instinct with e externalized death instinct. By contrast, the psychologists attribute it to the conjunction of desire with feelings of repulsion toward the body created by fear of mortality. “Because men find females sexually alluring,” they write, “they blame women for their own lustful urges, derogating and abusing them for reminding them of their own corporeal nature.” To try to demonstrate this, they had male subjects write essays about their death and then about times they lusted after a woman. Afterward, they had them mete out punishment in a court case where a man brutally assaulted his girlfriend. The subjects who had been reminded of their own death and lust meted out much milder punishments than the control group.

FINALLY, THE psychologists use their theory to reinterpret neuroses and psychoses. They argue that the fear of death lies at the bottom of phobias and obsessions, which serve to substitute the overriding fear of heights, spiders or dirt (for example) for an all-encompassing fear of death. The psychologists found that among people already afraid of spiders, those who were reminded of their mortality became much more afraid than those who were not reminded. They further explain schizophrenia as being based on a persistent fear of death to which the schizophrenic responds by creating worldviews of personal grandeur or persecution and depression as a failure of self-esteem to buffer fears of death.

Unlike Becker, the psychologists don’t entirely replace Freud’s theory of instinctuality and drives. Freud’s great contribution was in attempting to describe the interaction between the animal aspects of human nature and the special role of consciousness and volition. From thence came his understanding of the role of the unconscious and of repression and resistance. The psychologists believe there is a sexual drive and also an instinct for self-preservation. But, following the lead of Rank and Becker, the psychologists have sought to provide experimental evidence for an existential aspect to human behavior and belief rooted in human beings’ special awareness of their mortality.

Solomon, Greenberg and Pyszczynski can’t be said to have demonstrated in the most specific detail how the contemplation of mortality affects belief and action. Their experiments are suggestive rather than conclusive. Psychology is not physics. But what they have shown is that there is some connection between fears about mortality and people’s moral, cultural and political attitudes. That is a major contribution. If widely accepted, it could, perhaps, lead to measures that would reduce the polarization and demonization that remain so integral to politics in the United States and elsewhere.

If their work has a fault, it is that they cannot resist attempting to turn their analysis into therapeutic advice for individuals. They advocate “genuine” rather than “false esteem” and suggest that people with the genuine article “accept change as it comes and don’t spend a lot of time comparing themselves to others.” In a concluding section, they express their hope that humanity will “come to terms with death” and call for humans to “really grasp that being mortal, while terrifying, can also make our lives sublime by infusing us with courage, compassion, and concern for future generations.”

This kind of silly self-help advice flies in the face of their own grim analysis of the human condition. The fact is that we will not survive our deaths. The worldview defenses we construct are what Becker calls “vital lies.” They serve an important and constructive purpose, but they are illusions and delusions that allow us to keep our minds off the realization that after we die, like Shelley’s Ozymandias, “nothing besides remains.”

John B. Judis is a senior writer at National Journal and the author of Genesis: Truman, American Jews, and the Origins of the Arab-Israeli Conflict (Farrar, Straus and Giroux, 2014).