A group of American psychologists has discovered a simple way of turning ordinary people into fundamentalists and ideologues. Their method requires neither indoctrination nor isolation nor any form of brainwashing; indeed, it can be done anywhere and in a matter of minutes. It is just this: the researchers remind these ordinary folks that they will one day die. Illustration by Alex Hedworth

In one experiment, for example, the psychologists asked a group of Christian students to give their impressions of the personalities of two people. In all relevant respects, these two people were very similar – except one was a fellow Christian and the other Jewish. Under normal circumstances, participants showed no inclination to treat the two people differently. But if the students were first reminded of their mortality (e.g., by being asked to fill in a personality test that included questions about their attitude to their own death) then they were much more positive about their fellow Christian and more negative about the Jew.

The researchers behind this work – Sheldon Solomon, Jeff Greenberg and Tom Pyszczynski – were testing the hypothesis that most of what we do we do in order to protect us from the terror of death; what they call “Terror Management Theory”. Our sophisticated worldviews, they believe, exist primarily to convince us that we can defeat the Reaper. Therefore when he looms, scythe in hand, we cling all the more firmly to the shield of our beliefs.

This research, now spanning over 400 studies, shows what poets and philosophers have long known: that it is our struggle to defy death that gives shape to our civilisation. Or, as Socrates put it, the ways of men are incomprehensible until you see that they are striving for eternal life. This struggle to project ourselves into an unending future is the foundation of human achievement: the wellspring of religion, the architect of our cities and the impulse behind the arts.

That religions are very much a product of our yearning for immortality is perhaps obvious. The Buddha developed his particular doctrine of reincarnation on realising he would one day die; the spread of Islam relied on a particularly graphic portrayal of the rewards – or punishments – that awaited in the next life; and of course Christianity is explicitly a death-denying worldview: “Very truly, I tell you, whoever believes has eternal life,” as the Gospel of St John succinctly puts it.

Atheists and agnostics should not think that they are free from such comforting illusions of eternity. The psychologists, psychiatrists and anthropologists who developed Terror Management Theory have shown that almost all ideologies, from patriotism to communism to celebrity culture, function similarly in shielding us from death’s approach. Even the most enlightened of rationalists tend to have some solace-giving views that shape their action. It is this ubiquity of immortality strategies, even beyond the church and mosque, that makes their study so crucial to understanding ourselves.

In one now classic secular example, the researchers recruited court judges from Tucson in the USA. Half of these judges were reminded of their mortality (again with the otherwise innocuous personality test) and half were not. They were then all asked to rule on a hypothetical case of prostitution similar to those they ruled on every day. The judges who had first been reminded of their mortality set a bond (the equivalent of bail) nine times higher than those who hadn’t (averaging $455 compared to $50).

So just like the Christians, they reacted to the thought of death by clinging more fiercely to their worldview. Only in the judges’ case, their worldview was centred around law and order, as if stability and moral righteousness could keep the Reaper at bay. Other experiments have linked fear of death to the desire for fame and patriotism. It is even possible to make someone xenophobic just by asking them about immigration policy in front of a funeral parlour.

Thus the odds are that you too, dear reader, are possessed of some notion that promises the defeat of death. You might be tempted to think that popping vitamins and jogging can keep you one step ahead of the Reaper; that science will allow us to upload our minds on to computers; that something of you will remain in the great works you leave behind; or that you live on in the wisdom and DNA you have imparted to your children. Few, whether religious or not, can claim to be altogether free of such illusions.

The reason why we need such comforting stories is simple. Even though the desire for immortality can sound fanciful and metaphysical, it is in fact rooted in our most basic biological nature. We are, as Richard Dawkins puts it, “survival machines”. Like all creatures, we are only here because our ancestors strove to survive and reproduce – to propel themselves into the future. This is a truism in today’s life sciences: the preservation and reproduction of self in some form belong to all definitions of what life is; it is what makes the difference between evolution’s winners and losers.

But in humans this will to live becomes the will to live for ever. It is a consequence of our overgrown brains, with our ability to project into the future. Our desire to avoid death is not limited to face-to-face confrontations with predators or precipices – we can use our powerful imaginations to summon the prospect of all sorts of mortal perils at any moment. And, of course, we can see that the universal processes of disease and degeneration will eventually claim us too. Thus we alone of creatures must live with the fact of mortality; this is what WB Yeats meant when he wrote that “Man has created death”.

So we are born with the same desire to keep going that marks all living things, yet we can see that this desire will one day be thwarted. This realisation is potentially devastating: we must live in the knowledge that the worst thing that can possibly happen to us one day surely will. Extinction – the ultimate trauma, a personal apocalypse, the end of our individual universe – seems inevitable.

And thus we create our immortality strategies to cope with this terrifying insight. These strategies come in countless colours and creeds, from pyramid-building to yoga, from the Eucharist to cryonics, from the self-elevation of eternal fame to the self-submission of tribal loyalty. All human cultures have some way of reassuring us that death is not so bad as it seems.

Despite the apparent diversity of strategies they all in fact follow one of four basic forms. To put it metaphorically, there are just four paths purporting to lead up the Mount of the Immortals. Pharaohs, Popes, pop-stars and peasants – all have been struggling up one of these four paths in the hope of finding everlasting life at the top. It is the enormous generative and creative power of this struggle that has shaped human progress.

The first path is simply Staying Alive. Although it at first sounds unpromising, even absurd, every culture has had some myth of an elixir of life or fountain of youth that can keep us going in this body for ever. Now this strategy is as widespread as ever, as scientific progress holds out the promise of conquering ageing. But those seeking a back-up plan can find one in the second path: Resurrection. This is the belief that, although we must physically die, nonetheless we can physically rise again with the bodies we knew in life. The belief in physical resurrection is orthodoxy for Judaism, Christianity and Islam, but is also undergoing a reinvention for the scientific age as technologists dream of freezing their corpses so that they may one day live again.

However, those who would rather leave unreliable flesh and bone behind can choose the third path: survival as a Soul. The majority of people on Earth currently believe they have one, including two-thirds of people in the UK and even more in the US. And a general decline in church-going and other religious rituals is hardly having any impact on the widespread belief that we can live on in the ether. But those who doubt the reality of a spiritual substance can still take the fourth path: Legacy. This is as popular in today’s celebrity-obsessed culture as when Achilles chose eternal glory over a long life on the battlefield of Troy.

Can any of these possibly fulfil their promise? It is, after all, one thing to explain why we are prone to believe these stories, and quite another to ask if any of them are true. But such questioning could be a dangerous business: the American psychologist William McDougall, for example, argued that the passing away of belief in an afterlife “would be calamitous for our civilisation”. The Cambridge philosopher CD Broad, himself a sceptic, went so far as to argue “that the doctrine of human immortality (whether it be in fact true or false) is one of these socially valuable ‘myths’ which the State ought to remove from the arena of public discussion.”

But the State, fortunately, has not so acted and we are free to find our own way. And this way need not be blindly following the millions who have trodden these four paths before us. Instead, by reflecting on what drives us to struggle up the Mount of the Immortals, we might learn to master that drive. And by reflecting on where those four paths have taken us, we might learn to harness their creative power while avoiding their dark side of xenophobia and extremism.

Indeed, by reflecting on our quest for immortality, we might even find that it is possible to live without it. We might find that the very limit to our time is what makes it valuable; that if we stop dreaming of an indefinite future, we can live better in the here and now. This would not be easy: we are born to project ourselves forward and are easy prey for any ideology that promises we can do so without end. But with practice and thought it might just be possible. As the Psalmist tells us: “teach us to number our days, that we may apply our hearts unto wisdom”.

Immortality: The Quest to Live Forever and How it Drives Civilisation by Stephen Caveis published by Biteback. RA readers can buy the paperback at the special price of £5.99 (RRP: £9.99) – simply visit the Biteback promotion page and enter the code "RAIMMORTALITY".