Citizens' views on Muslim immigrants in Western democracies often stem from a rejection of fundamentalist religiosity rather than inherent dislike. This study employed a representative online survey experiment conducted in the UK during summer 2015 to clarify this phenomenon.

Key findings reveal two surprising insights: citizens do not view Muslim immigrants more negatively than Christian ones, and political identity plays only a secondary role compared to religious fundamentalism. The results demonstrate that unease with Muslim immigration primarily arises from opposition to specific religious behaviors — what the study terms 'fundamentalist religiosity'.

The survey uncovered a distinct pattern: while all groups express some criticism of religion, those identifying as politically left or culturally liberal are actually more critical than right-leaning individuals. This double-sided hostility suggests that current political debates about Muslim immigration might be reframed around secular vs fundamentalist religious attitudes.

• Survey Experiment in UK: 2015 summer wave allowed for representative measurements of public sentiment toward Muslim immigrants

• Fundamentalist Religiosity: Citizens' negative reactions primarily driven by rejection of overtly devout religious behaviors rather than ethnicity or faith alone

• Political Ideology's Role: While expected to matter, political leanings played a less significant role in attitudes than anticipated

• Double Opposition Pattern: Both left/liberal and right/conservative groups displayed criticism toward religious fundamentalism