Correction: An earlier version of this article incorrectly extrapolated data from the Pew Research Center’s 2013 survey report, “The World’s Muslims: Religion, Politics and Society,” regarding the percentage of Muslims in Egypt and Pakistan who support the death penalty for leaving Islam. The correct figures, based on the 2013 Pew Research Center report, are 88% of Muslims in Egypt and 62% of Muslims in Pakistan favor the death penalty for people who leave the Muslim religion.

The Pew Research Center's vast new study on the views and attitudes of global Muslim populations was bound to create controversy. Like the U.S. public knowledge polls that find that one-third of Americans can't name the vice president, Pew's report includes some less-than-flattering pieces of data. And while it's important not to generalize about entire populations or demographic groups based on one study, some of these numbers are difficult to ignore. One of the questions, which Pew asked of Muslims in 38 countries from Europe, Asia, Africa and the Middle East, was whether or not they support making sharia the official law in the country. In many countries, the answer was overwhelmingly yes, although Pew notes that many respondents said sharia should apply only to Muslims and, just as importantly, that "Muslims differ widely in how they interpret certain aspects of sharia, including whether divorce and family planning are morally acceptable." Many respondents reject the stricter laws and punishments for which sharia is often, fairly or unfairly, known in the West. In other words, just because some people say they support sharia law does not mean they want to make their neighbors live in a 9th-century-style caliphate. Still, amid an otherwise innocuous or even reassuring report, Pew's study found some disturbing details. One that jumped out for me was the alarmingly high share of Muslims in some Middle Eastern and South Asian countries who say they support the death penalty for any Muslim who leaves the faith or converts to another. In fact, according to the 2013 Pew Research Center report, 88 percent of Muslims in Egypt and 62 percent of Muslims in Pakistan favor the death penalty for people who leave the Muslim religion. This is also the majority view among Muslims in Malaysia, Jordan and the Palestinian territories. It's important to note, though, that this view is not widely held in all Muslim countries or even among Muslims in these regions. In Bangladesh, another majority Muslim South Asian state that has a shared heritage with Pakistan, it is about half as prevalent, with 36 percent saying they support it. Fewer than one in six Tunisian Muslims hold the view, as do fewer than one in seven Muslims in Lebanon, which has a strong Christian minority. The view is especially rare among Central Asian and European Muslims. Only 6 percent of Russian Muslims agree that converts from Islam should face death, as do 1 percent of Albanian Muslims and, at the bottom of the chart, 0.5 percent of Kazakhs.

Pew's data shows the share of Muslims who support sharia and the share of these pro-sharia Muslims who back this policy. Some of the Pew data are charted at right. Leaving the faith is a particularly sensitive issue in Islam, which was initially founded in part as a sort of community. Abandoning Islam is traditionally considered not just apostasy, as it is in other religions, but a specific transgression called "ridda." In the first days of Islam, the religion was also a physical community under siege from outside forces and facing the possibility of fracturing within. To leave the faith was also to abandon the larger community, a crime considered akin to treason in the way we understand it in the West. Of course, times have changed significantly over the past 13 or 14 centuries, and a lone Muslim deciding to adopt a different faith or give it up altogether is no longer a practical threat to his or her community in the way that he or she might have been back then. But the religious pronouncements commanding punishment for ridda are still right there in the scripture, which may explain in part why this view persists. It's also important to note that majorities of Muslims in the countries surveyed, sometimes vast majorities, said they support religious freedom. That includes, for example, more than 75 percent of Egyptians and more than 95 percent of Pakistanis. It might seem like a glaring contradiction. And it is a contradiction, but it might make a little more sense that so many people could hold seemingly mutually exclusive views -- religious freedom is good, but anyone who leaves Islam should be executed -- if one understands the particular history of apostasy in Islam.