Numbers, Facts and Trends Shaping Your World

The World’s Muslims: Unity and Diversity


From its origin on the Arabian Peninsula in the seventh century C.E., Islam has grown into a worldwide religion with more than 1.6 billion adherents – nearly a quarter of the world’s population.1 Today, Muslims live on all inhabited continents and embody a wide range of races, ethnicities and cultures. What beliefs and practices unite these diverse peoples into a single religious community, or ummah? And how do their religious convictions and observances vary?

This report by the Pew Research Center’s Forum on Religion & Public Life seeks to describe both the unity and the diversity of Islam around the globe. It is based on more than 38,000 face-to-face interviews conducted in over 80 languages with Muslims in 39 countries and territories that collectively are home to roughly two-thirds (67%) of all Muslims in the world. The survey includes every country that has a Muslim population of more than 10 million, except those (such as China, India, Iran, Saudi Arabia and Syria) where political sensitivities or security concerns prevented opinion research among Muslims.

Unity and diversity are themes that emerge naturally from the survey results. On what are often considered Islam’s articles of faith and “pillars” of practice, there is much commonality among Muslims around the world. But on other important questions, such as whether Islam is open to more than one correct interpretation or which groups should be considered part of the Muslim community, there are substantial differences of opinion. The survey also suggests that many Muslims do not see themselves as belonging to any particular sect: Fully a quarter of the Muslims surveyed identify themselves neither as Sunni nor as Shia but as “just a Muslim.”

The survey was conducted in two waves. Fifteen sub-Saharan African countries with substantial Muslim populations were surveyed in 2008-2009, and some of those findings previously were analyzed in the Pew Forum report “Tolerance and Tension: Islam and Christianity in Sub-Saharan Africa.” An additional 24 countries in Africa, Asia and Europe were surveyed in 2011-2012; those results are published here for the first time. This report on religious beliefs and practices, however, is just the first of two planned analyses of the survey data. The Pew Forum plans to issue a second report, focusing on Muslims’ social and political attitudes, in late 2012 or early 2013.


The Pew Forum’s global survey of Islam is part of a larger effort, the Pew-Templeton Global Religious Futures project, which analyzes religious change and its impact on societies around the world. Previous studies produced under the Pew-Templeton initiative, jointly funded by The Pew Charitable Trusts and the John Templeton Foundation, include “Faith on the Move: The Religious Affiliation of International Migrants” (March 2012), “Global Christianity: A Report on the Size and Distribution of the World’s Christian Population” (December 2011), “Rising Restrictions on Religion” (August 2011), “Global Survey of Evangelical Protestant Leaders” (June 2011), “The Future of the Global Muslim Population: Projections for 2010-2030” (January 2011), “Global Restrictions on Religion” (December 2009), “Mapping the Global Muslim Population: A Report on the Size and Distribution of the World’s Muslim Population” (October 2009) and “Spirit and Power: A 10-Country Survey of Pentecostals” (October 2006).

The primary researcher for “The World’s Muslims: Unity and Diversity” was James Bell, the Pew Forum’s director of international survey research. He received valuable research assistance from Michael Robbins, Neha Sahgal and Katie Simmons. Fieldwork was carried out under the direction of Princeton Survey Research Associates International and Opinion Research Business; we particularly wish to thank Mary McIntosh and Jonathan Best of PSRAI and Johnny Heald and Cara Carter at ORB.

Amaney Jamal, Associate Professor of Politics at Princeton University, served as a special adviser. In the design of the survey questions and preparation of this report, the Pew Forum also was fortunate to be able to call on the expertise of several other academic experts, including Asma Afsaruddin of Indiana University, Xavier Bougarel of The National Centre for Scientific Research (Paris), Michael Cook of Princeton University, David Damrel of the University of South Carolina, Nile Green of the University of California, Los Angeles, Robert Hefner of Boston University, Marcia Hermansen of Loyola University Chicago, Leonard Lewisohn of the University of Exeter (United Kingdom), Peter Mandaville of George Mason University, Vali Nasr of Tufts University, Steven Prothero of Boston University, Asifa Quraishi of the University of Wisconsin Law School, Farid Senzai of Santa Clara University and Shibley Telhami of the University of Maryland.

While the survey design was guided by the counsel of our advisers, contractors and consultants, the Pew Forum is solely responsible for the interpretation and reporting of the data.

Luis Lugo, Director Alan Cooperman, Associate Director for Research


1 For further information on the global and regional distribution of Muslims, see the Pew Forum’s 2011 report “The Future of the Global Muslim Population” and 2009 report “Mapping the Global Muslim Population.” (return to text)

Photo Credit: © SZE FEI WONG / istockphoto

Icon for promotion number 1

Sign up for our weekly newsletter

Fresh data delivery Saturday mornings

Icon for promotion number 1

Sign up for The Briefing

Weekly updates on the world of news & information