Most of the world's 1.6 billion Muslims identify as either Sunni or Shia — the two main branches of Islam and a source of political and social strife in the Middle East.
But a growing number of faithful want to be known as "just Muslims," according to a global survey of the world's second largest religion, behind Christianity, by the Pew Research Center's Forum for Religion & Public Life.
While the report, "The World's Muslims: Unity and Diversity," shows differing views on Muslim identity, commitment and practices, the data gleaned from 38,000 interviews in 39 countries also reveals a universal solidarity in their belief in God and their adherence to Islam's key rituals such as Ramadan, a month-long fast that concludes Sunday, Aug. 19.
"Whatever their personal reasons are for participating or whether they believe in certain things or not, they're all part of a (global Muslim) community and I think that comes across in these findings," said Jim Bell, director of international survey research for the Pew Research Center.
The report released earlier this month did not delve into the political implications of the responses gathered over a four-year period from 2008-2012. But the findings do offer some insight into how generational and geographical circumstances influence how Muslims view themselves and practice their faith.
The Middle East and Northern Africa is where Muslims most strongly identify as either Sunni or Shia, the survey found, and where views are mixed on whether the minority Shia are accepted as Muslims. The two sects were created by a leadership succession dispute following the death of Islam's founding prophet Muhammad, but the political rift has widened over the centuries as it has taken on theological distinctions and differences in religious practices.
But the Pew report showed one-quarter of those surveyed were either unfamiliar with the Sunni-Shia distinction or found it unimportant.
"This is especially true across Southern and Eastern Europe, as well as in Central Asia, where medians of at least 50 percent describe themselves as 'just a Muslim,'" the Pew report stated. In Indonesia, where nearly 13 percent of the world's Muslims live, 56 percent of those surveyed did not identify with either sect.
Researchers were surprised, Bell said, to find that where one would assume strong animosity between the two sects — in Lebanon and Iraq, where large populations of both sects reside — is actually where Sunnis are at least 23 to 28 percentage points more likely than elsewhere in the Middle East to recognize Shias as Muslims.
"Our findings suggest that maybe living side by side with one another actually increases rather than decreases tolerance," Bell said.
Researchers also found that in Lebanon younger Sunnis are more accepting of Shias than Sunnis older than 35. "It may be that the generation that came of age during some of the most tense years of conflict in that country are less inclined to accept Shias as Muslims and that the generation that didn't have the same experience is more accepting," Bell observed.
Researchers were unable to survey in either Saudi Arabia or Iran — where the animosity between Sunni and Shia is particularly acute — or in Syria, China and India, because political sensitivities and security concerns prevented polling of those sizeable Muslim populations.
While there are differences in how Muslims identify themselves, they are united by their core beliefs and rituals, the survey found.
Belief in one God and his Prophet Muhammad, angels, fate or predestination and Judgment Day are nearly universal, as is the observance of the Ramadan fast. A large majority also said they participate in annual almsgiving to help the poor and needy.
Men and women also tend to be similar in expressing the role Islam plays in their lives and in their daily practice of praying and reading the Quran, Islam's sacred book.
"The one exception to this pattern is mosque attendance: women are much more likely than men to say they never visit their local mosque. This gender gap is largest in South Asia and Central Asia," the report said.
Differences emerged geographically and generationally when Muslims were asked how important religion is to them and how often they attend mosque, pray and read or listen to readings of the Quran.
In sub-Saharan Africa, Southeast Asia and South Asia, about 9-in-10 said religion plays an important role in their lives. Similar attitudes were expressed by large majorities in the Middle East, with the exception of Lebanon, where 59 percent said religion is important.
But stark differences appeared in Central Asia, Russia and the Balkans, where generally fewer than half of the Muslims living in the former communist countries said religion was important in their lives. Albanian Muslims had the lowest level of religious commitment at 15 percent, while Turkey, where Muslims did not live under communist rule, was the highest at 67 percent.
Hakan Yavuz, a political science professor at the University of Utah who has studied Islamic culture in Central Asia, said Muslims were small in number and isolated during the colonial and Communist reigns over the region, making sectarian distinctions largely irrelevant and minimizing the role of religion.
"The scientific atheism that was taught under the Communist system was somewhat successful" in purging belief and importance of religion in everyday life, Yavuz said.
As a result, he explained, the practice of Islam is more internalized and spiritual than outwardly through the practice of prayer, fasting and other measures of commitment Pew researchers used.
But Yavuz explained that since the breakup of the Soviet Union, a newer generation that is more knowledgeable about religion and more connected to the larger Muslim world is spurring a revival of Islam in the region.
In fact, the Pew researchers found that Russia was an anomaly among Muslims worldwide. In that country 48 percent of Muslims ages 18-34 describe religion as very important to their lives, compared with 41 percent of those 35 and older. Elsewhere in the world, younger Muslims were less religious than their elders, although in the Middle East the generation gap is narrow, with large majorities of young and old saying their faith is central to their lives.
The Pew Forum surveyed American Muslims in 2011 and found, as with their counterparts throughout the world, overwhelming acceptance of Islam's core beliefs. But the importance placed on religion in their daily life was less among U.S. Muslims, who were also less observant to the basic practices, such as prayer and mosque attendance.
Where American Muslims stood out from the rest of the world, however, was their openness to different interpretations of Islam. A majority of U.S. Muslims (57 percent) said Islam can be understood in more than one way, while the median in countries outside the United States was just 27 percent.
But Yavuz, author of the forthcoming book "Toward Islamic Enlightenment," to be published by Oxford University Press, predicts that gap will narrow in the future.
He explained that between the rigid interpretation of Islam that will thrive in less stable nations and the more flexible interpretations found in Turkey, Indonesia and the United States, numerous other trends will take hold as Muslims find ways to embrace modernity and hold on to their faith.
"The Muslim world is so diverse socially and economically that we will not have one trajectory, but multiple trajectories" of Islam in the future, he said.