Agnostics, however, do become more willing to believe in God when reminded of death. The only catch is that they're equally as likely to believe in Buddha or Allah as the Christian deity, even though all the agnostics in the study were  American and thus more likely to be exposed to Christian beliefs.

The findings confirm that while religion can help people deal with death, we all manage our own existential fears of dying through our pre-existing worldview, the researchers report in an upcoming issue of the journal Personality and Social Psychology Bulletin.

"These studies offer an improved understanding of how and why religious individuals tend to believe so strongly in their own religion’s gods yet deny the gods of competing religions," the researchers wrote.

Plenty of research has shown that religion, which frequently promises an everlasting afterlife, helps people cope with the fact that they will die someday. But this use of religion is not universal. One 2006 study found that thoughts of death increased belief in supernatural figures in general for religious people. That study did not separate atheists from agnostics, nor did it examine how specific religious beliefs might influence the sort of supernatural figures a person might believe in. [ Top 10 Unexplained Phenomena ]

To find out, University of Missouri psychologist Kenneth Vail III and colleagues recruited 26 Christians, 28 atheists, 40 Muslims and 28 agnostics.. The participants were American college students, except for the Muslims, who were Iranians going to school in Iran. Each participant was tasked with writing either a brief essay about how they felt about their own death or a religiously neutral topic, such as loneliness or how to cope when plans go awry.

After a brief verbal task to distract the participants from the true purpose of the study, they filled out questionnaires about their religious beliefs, including their faith in the Christian God or Jesus, Buddha and Allah.

Unsurprisingly, when Christians thought of death, they became firmer in their beliefs than those Christians who hadn't been reminded of their mortality. They also became less accepting of Allah and Buddha, suggesting a closer adherence to their own worldview. Likewise, Muslims who thought of death became more faithful to Allah and less accepting of Buddha or the Christian God.