An Ipsos Mori survey that measured the gap between public perception and reality in 40 countries in 2016 found French respondents were by far the most likely to overstate their country’s current and projected Muslim population.
The average French estimate was that 31% of the population was Muslim – almost one in three residents. According to Pew Research, France’s Muslim population actually stood at 7.5% in 2010, or one in 13 people.
The French were not the only ones to hold such misconceptions: Italian, German and Belgian respondents all guessed that more than a fifth of the resident population was Muslim, while in reality the figure ranges from 3.7% in Italy to 7% in Belgium. All three countries also greatly overstated the expected proportion of Muslim residents in 2020.The graph below shows the results for several countries, including the U.S. You can readily imagine that the discussions in the media about refugees--especially inspired by the crisis in Syria--have increased and distorted the public perception about the presence of Muslims in western countries.