A study by the Pew Forum on Religion and Public Life finds that government restrictions and social hostility toward religions are rising in the world's most populous countries.
More than 2.2 billion people, or nearly a third of the world's 6.9 billion total population, live in countries where restrictions or hostilities increased between mid-2006 and mid-2009, the researchers said.
In six of the world's 25 most populous countries, substantial increases were reported because of rising levels of social hostility -- China, Nigeria, Russia, Thailand, the United Kingdom, and Vietnam. In two of those nations, Egypt and France, the increases resulted mainly from government restrictions.
"Countries with substantial increases generally already had high levels of restriction or hostility," Brian Grim, the lead researcher, said in an interview.
By contrast, he said, nearly half of the countries that had substantial decreases in restrictions or hostilities already scored low.
The data included comprehensive analysis of concrete government policies or actions on religious practices, and verified incidents of religious violence or intolerance by social groups or individuals.
The study did not include recent developments such as the "Arab Spring" revolution that took place earlier this year in northern Africa and the Middle East, nor the massacre in Norway committed last month.
Mr. Grim said northern Africa and the Middle East was the highest of five global regions in regard to government restrictions and social hostilities toward religion.
"It's hard to pinpoint the exact role religion plays in what's going on, but it's very fair to say religion overlays itself on the social and political conditions of a country," he said.
The study recorded an "uptick" in hostilities toward minorities in Norway, where a terrorist in July killed more than 70 people in a rampage apparently motivated by religious and ethnic hatred.
"We had already seen social hostilities rising in the United Kingdom, Denmark, and Sweden, and generally across Europe. What we were observing was again part of the context in which the tragedy in Norway happened," Mr. Grim said.
The more populous nations with the lowest government restrictions and levels of social hostility toward religion included the United States, Brazil, Japan, Italy, and South Africa.
"Generally, the United States has low government restrictions," Mr. Grim said. But social hostilities rose from the previous study, which covered mid-2006 to mid-2008.
"Each year, more than 1,300 religiously based hate crimes are reported to the FBI by local law enforcement officials" in the United States, he said.
The report said Christians and Muslims, who together comprise more than half of the world's population, were harassed in the largest number of countries -- Christians in 130 countries and Muslims in 117.
Jews, who make up less than 1 percent of the world's population, faced restrictions or hostility in 75 countries.
Mr. Grim said that correlates with the fact that minorities generally "bear the brunt" of religious bias, and Jews are in the minority everywhere except Israel.
The full 112-page report is available online at pewforum.org.