About 75 percent of Americans still identify as Christians, after a 5-percent drop since 2008, according to a new Gallup poll, which also shows that the number of those having no formal religious identification has increased by 5 percent, amounting to 20 percent.
A review of more than 174,000 interviews conducted by Gallup this year shows that three-quarters of American adults identify as Christians, little changed from 2014, but down from 80 percent eight years ago, the survey says.
"Despite these changes, America remains a predominantly Christian nation, and with 94% of those who identify with a religion saying they are Christian," the poll notes, adding that the percentage of Christians is highest among older Americans and decreases with each progressively younger age group.
The Christian category in the poll includes Catholics, Protestants, Mormons and non-denominational Christians.
In 2015, 24 percent of Americans identify as Catholic, 50 percent as Protestant or as members of another non-Catholic Christian religion, and 2 percent as Mormon, according to Gallup.
About 20 percent of Americans have no formal religious identification, which is up five percentage points since 2008, the survey says. About 5 percent of Americans identify with a non-Christian religion, which has been essentially constant over this time period, it adds.
The poll shows that the percentage of Christians is highest among older Americans and decreases with each progressively younger age group.
"One key to the future of Christian representation in the U.S. population will be shifts in the religious identification of today's youngest cohorts," pollsters say. "Traditionally, Americans have become more likely to identify with a religion as they age through their 30s and 40s and get married and have children. If this pattern does not occur in the same way it has in the past, the percentage of Christians nationwide will likely continue to shrink."
A major religious trend in the U.S. has been the increasing number of Americans who say they do not have a formal religious identification, known as "nones," the survey notes.
"This expansion has been accompanied by the shrinkage in the number of people who identify as Christian," it adds. "More than 95% of Americans identified as Christian in the 1950s, and 80% did so as recently as eight years ago. While the 5% of the population who identify with a non-Christian faith is higher than it was decades ago, it has not shown significant change over the past eight years."