What citizens think about Muslim immigrants has important implications for some of the most pressing challenges facing Western democracies. To advance contemporary understanding of what ‘Islamophobia’ really is – for example, whether it is a dislike based on immigrants’ ethnic background, religious identity or specific religious behaviors – this study fielded a representative online survey experiment in the UK in summer 2015. The results suggest that Muslim immigrants are not per se viewed more negatively than Christian immigrants. Instead, the study finds evidence that citizens’ uneasiness with Muslim immigration is first and foremost the result of a rejection of fundamentalist forms of religiosity. This suggests that common explanations, which are based on simple dichotomies between liberal supporters and conservative critics of immigration, need to be re-evaluated. While the politically left and culturally liberal have more positive attitudes toward immigrants than right-leaning individuals and conservatives, they are also far more critical of religious groups. The study concludes that a large part of the current political controversy over Muslim immigration is related to this double opposition: it is less about immigrants versus natives or even Muslim versus Christians than about political liberalism versus religious fundamentalism.

Cytoplasmic incompatibility consists of sterility in cross matings, the crossing type being maternally inherited. It can be explained by the action of Wolbachia symbionts which are transmitted through the egg cytoplasm and leave an imprint on the sperm which prevents it fertilizing unless it is ‘rescued’ by the action of the same type of Wolbachia in the egg. Thus matings between infected males and uninfected females are sterile, but the reciprocal matings are fertile. Hence uninfected females are at risk of failing to transmit their uninfected cytoplasm if they cross mate, but infected females are at no such risk. Therefore natural selection favours the infected state and in two wild insect populations the infection has been observed spreading. If a gene for inability to transmit malaria could be introduced into Wolbachia and if this could be introduced into Anopheles (where these symbionts appear not to occur naturally), release of a limited number of such insects should trigger a process of displacement of malaria vectors, by the non-vector type. A simple model is used to demonstrate the limitations to this process which would be introduced by immigration.