THE THOUGHT of shuffling off our mortal coil can make all of us a little squeamish. But avoiding the idea of death entirely means ignoring the role it can play in determining our actions. Consider the following scenario:

You’re visiting a friend who lives on the 20th floor of an old inner-city apartment building. It’s the middle of the night when you are suddenly awakened from a deep sleep by the sound of screams and the choking smell of smoke. You reach over to the nightstand and turn on the light. You are shocked to find the room filling fast with thick clouds of smoke. You run to the door and reach for the handle. You pull back in pain as the intense heat of the knob scalds you violently. Grabbing a blanket off the bed and using it as protection, you manage to turn the handle and open the door. Almost immediately a huge wave of flame and smoke roars into the room, knocking you back and literally off your feet. There is no way to leave the room. It is getting very hard to breathe, and the heat from the flames is almost unbearable. Panicked, you scramble to the only window in the room and try to open it. As you struggle, you realize the old window is painted shut around all the edges. It doesn’t budge. Your eyes are barely open now, filled with tears from the smoke. You try calling out for help, but the air to form the words is not there. You drop to the floor, hoping to escape the rising smoke, but it is too late. The room is filled top to bottom with thick fumes and is nearly entirely in flames. With your heart pounding, it suddenly hits you, as time seems to stand still, that you are literally moments away from dying. The inevitable unknown that was always waiting for you has finally arrived. Out of breath and weak, you shut your eyes and wait for the end.

Yipes! What an excruciating and terrifying way to go. If you’re like me, you experienced a moment of panic reading that passage. But relax—you’re okay. The above scenario is just an experimental manipulation, one meant to jump-start your existential mind.

Or one of your two existential minds—if an emerging theory is correct. Psychological scientists Laura E. R. Blackie and Philip J. Cozzolino of the University of Essex in England have been exploring the idea that we are all governed by two disparate existential systems, each with its own distinct method of processing the idea of death. Both existential minds have the power to meaningfully change our attitudes and actions, but they work in very different—almost opposite—ways.

Of Two Minds

One of our systems of existential thinking responds to the abstract concept of dying, so that even subtle everyday reminders of death, such as driving past a cemetery, prime the mind to ward off existential terror. This system tends to bolster our already existing beliefs, both religious and cultural, as a way of affirming life. For instance, studies have shown that after people reflect on what will happen when they die, they become more nationalistic and defensive about their political beliefs.

The second existential system is vivid, concrete and highly personal; it is triggered not by subtle and abstract thoughts but by actually coming face to face with death. When this system is primed into action—as the above apartment fire scenario is meant to do—our very personal sense of mortality can lead us to reexamine our priorities in life, to become more grateful and to grow spiritually. Soldiers who have seen combat and people who have lived through life-threatening illnesses often report these shifts in attitude.

Priority Shifts

Therefore, some thoughts of death shore up our beliefs, and other types of reflection make us reexamine them. Which kind leads to a better life? For their experiment, Blackie and Cozzolino recruited volunteers aged 17 to 76 and primed them in different ways. Some answered open-ended questions about death, to remind them of their mortality in a general way, whereas others imagined they were trapped and dying in the burning apartment by reading the paragraph above. Another group, the control subjects, thought about going to the dentist—unpleasant but not life-threatening. Then they all read one of two fake news stories. One story said that blood donations were at “record lows” and thus the need for blood donations was high. The other said the opposite, that supplies were at “record highs,” so the need for donations was low. Finally, the researchers gave all the participants the opportunity to volunteer as blood donors.

The scientists were hoping to see which group became more altruistic, and they succeeded. The findings were an interesting mix. Those primed in an abstract way by general thoughts about dying were more generous than the dentist-imagining controls, but only when the need was high. This result suggests that the abstract thinkers were reaffirming the societal expectation that it is good to give to the needy—not exactly a sweeping personal epiphany.

Those who were vividly primed by thoughts of their own death in flames, however, were even more generous than those primed in a more subtle and abstract way. They were willing to give blood whether the need was high or low, suggesting they had undergone a fundamental reexamination of their values.

Why would this difference exist? One possibility, as the scientists write in the online version of the journal Psychological Science, is that our abstract existential system has no tolerance for the gory details of death; in fact, abstract thoughts of death generate an aversion to bodily fluids, including blood. Indeed, previous experiments have supported this idea: after being reminded of their mortality, people are more squeamish about physical trauma. In the current study this aversion to blood was not strong enough to trump the cultural expectation that we should help those in need—but it carefully meted out generosity to those truly in the most need.

People who have come close to perishing, on the other hand, see things differently. For them, blood is not something aversive at all—it is the stuff of life.