CHICAGO (CBS) — The older you are, the more likely you are to believe in God, according to a new University of Chicago study.

As WBBM Newsradio’s Bernie Tafoya reports, researchers from the National Opinion Research Center at the U of C mined data from three surveys conducted in 30 countries between 1991 and 2008 for the study “Belief about God across Time and Countries.”

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

They found that 43 percent of those 68 or older are certain that there is a God, while only 23 percent of those 27 and under are similarly certain. The numbers vastly favored God in the United States, where 54 percent of those younger than 28, and 66 percent of those older than 68, said they believed in God.

The researchers surmise older people are more likely to believe in God because of a growing realization that death is not too far off, relatively speaking.

Dr. Tom W. Smith says belief in God also varies from country to country.

“In (the former) East Germany, down to barely 10 percent of people having a strong belief in God, to Chile or the Philippines, other countries, with over 90 percent of people being certain that God exists,” he said.

The study found that atheism is strongest in northern European countries, such as those in Scandinavia and the former Soviet republics and Eastern bloc countries – with the exception of Poland.

The Philippines had the highest rate of belief in God of all, with 94 percent.

In the United States, 81 percent of survey respondents said they believe in God. A total of 68 percent of respondents agreed with the belief that God is concerned with people in a personal way.

The study found that by most measures, belief in God is declining worldwide. But it is increasing in Russia, Slovenia and Israel, the survey said.