Members of The Church of Jesus Christ of Latter-day Saints have the largest families in America, among both religious and nonreligious groups.

Second place goes to Muslims, according to a survey released Monday.

The "U.S. Religious Landscape Survey" was prepared by the Pew Forum on Religious and Public Life, based in Washington, D.C. The forum is funded by the Pew Charitable Trusts.

The survey's summary says, "No matter how rigorous, however, all surveys have their limitations and the Landscape Survey is no exception. ... These limitations are particularly apparent when it comes to providing definitive figures on membership in religious groups."

That seems to skew the membership figures for the LDS group downward. The survey was conducted only among adults 18 and older, and many LDS families have children under 18, as evidenced by the finding that members of the church have the largest families.

Also, the results only include members of a religion who live in America, while the LDS membership is worldwide.

Chief findings are that 78.4 percent of the sampling of 35,000 Americans say they are Christians. The study found that 51.3 percent of all Americans are Protestant, 23.9 percent are Catholic, 1.7 percent are LDS, Jehovah's Witnesses make up 0.7 percent, Orthodox Christians are less than 0.6 percent and other Christians are 0.3 percent.

Last July, the U.S. population was about 301.6 million, according to the U.S. Census Bureau. If the survey is accurate, the LDS faith's membership in America would amount to more than 5.1 million adults.

About 1.7 percent of Americans are Jewish, 0.7 percent are Buddhist, 0.6 percent are Muslims, 0.4 percent are Hindu, other world religions are less than 0.3 percent.

Unaffiliated make up 16.1 percent of Americans, including atheists (1.6 percent), agnostics (2.4 percent), "nothing in particular" (12.1 percent) and religious but unaffiliated (5.8 percent). Those who said they didn't know or refused to answer were 0.8 percent of the sampling.

Key findings include:

• Members of the LDS Church have the most children living at home. Mormon households with four or more children are 9 percent of the membership, compared with 3 percent nationally. Runners-up are Muslims, with 6 percent. Only 4 percent of Catholics have four or more children.

Mormons also lead in households with three children — 12 percent — compared with a national average of 6 percent. Concerning homes with two children, the LDS figure is a little above average, at 14 percent, compared with 13 percent nationally; the survey shows that LDS families with one child are 14 percent, while nationally the average is 13 percent.

Another indication of family size is the percentage of those surveyed who have no children. The national average is 68 percent, according to Pew. But among the LDS members surveyed, it's only 51 percent, the smallest proportion of any group surveyed.

• More LDS members live in the West than in the rest of the country combined, with 76 percent of the 581 members of the church surveyed calling this region home. Not surprisingly, Utah has the highest proportion of what the survey calls "Mormon tradition," at 58 percent of the state's population. In Idaho, 23 percent are "Mormon tradition"; in Nevada it's 11 percent; Oregon, 5 percent; Montana-Wyoming (the states are combined), 5 percent; Arizona, 4 percent.

Utah's non-LDS population includes evangelical Protestants, 7 percent (compared with 26 percent of the national population); mainline Protestant, 6 percent (18 percent nationwide); members of historically black Protestant churches, 1 percent (7 percent nationally); Catholics, 10 percent (24 percent nationally); Orthodox Christians, less than 0.5 percent (1 percent nationally); Jehovah's Witness tradition, less than 0.5 percent (1 percent nationally); other Christians, less than 0.5 percent (same as national figures); Jewish tradition, less than 0.5 percent (2 percent nationally); Muslim tradition, less than 0.5 percent (1 percent of the American population); Buddhist tradition, less than 0.5 percent (1 percent across the country), Hindus, less than 0.5 percent (same as national figures); other world religions, less than 0.5 percent (same as national figures); other faiths, 1 percent (same as national), unaffiliated, 16 percent (same proportion as national figures), and don't know or refused, 1 percent (less than 0.5 percent nationally).

• Hindus are the most likely to be married, at 78 percent; LDS Church members are second, with 71 percent. The national average is 54 percent.

• The LDS Church membership is younger than most. The national average for members 18 to 29 is 20 percent, while among Mormons it's 24 percent. For members 30 to 49, the national figures are 39 percent, but Mormons have 42 percent; for 50 to 64 years old, the national total is 25 percent, but for LDS members, it's 19 percent; throughout America, 16 percent of those surveyed are 65 and over, while Mormons have 15 percent in that age range. For this survey, 555 Mormons responded.

The totals for this section include other faiths and unaffiliated.

• The LDS faith is largely white, but not as uniformly so as several other denominations. Mormons are 86 percent white non-Hispanic; 3 percent black;, 2 percent Asian; 3 percent other or mixed, non-Hispanic; 1 percent Hispanic, in a sampling of 571. By comparison, 71 percent are white. Jews are 95 percent white, and members of mainline Protestant Churches are 91 percent white.

• Jewish people have the largest proportion earning more than $100,000 yearly, at 46 percent; LDS Church members have 16 percent in that income category, the same as the national figure.

• The best-educated people in the country, according to the study, are Hindus, with 74 percent college graduates or people with post-graduate schooling; they are followed by Jews, 59 percent; Buddhists, 48 percent; Orthodox Christians, 46 percent; other Christians, 40 percent; other faiths, 39 percent; members of mainline Protestant churches, 34 percent; unaffiliated, 29 percent; Mormons, 28 percent; Catholics, 26 percent; Muslims, 24 percent; members of evangelical Christian churches, 20 percent; members of historically black Protestant churches, 16 percent; Jehovah's Witnesses, 9 percent.

• Nearly half, 44 percent, of U.S. adults have left the faith of their childhood for another religion or no religion at all. The survey shows the country is 78 percent Christian and about to lose its status as a majority Protestant nation, at 51 percent and slipping. Luis Lugo, director of the Pew Forum on Religion and Public Life, wrote in the report that the group will be releasing another survey in the spring concerned with religious beliefs.

Lugo wrote, "We will extensively probe such topics as belief in God and the afterlife, attitudes toward the authority of sacred writings, frequency of worship attendance and prayer, views on abortion, attitudes about the proper role of government and opinions on foreign affairs."

Contributing: Eric Gorski, Associated Press

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