Terrorism, perpetrators, and polarization: evidence from natural experiments

We analyze whether affective polarization can be aggravated by terrorism violence. Terrorist attacks intensify preexisting ideological worldviews and partisan leanings and bring divisive political issues to the fore. Yet, they can also generate strong feelings of cohesion, solidarity, and unity as individuals from the entire political spectrum come together. To identify causal effects, we exploit a series of natural experiments in Great Britain and leverage the timing of fatal far-right and Islamic terrorist attacks and the date of interview of respondents in the British Election Study. We find that Islamic attacks increase affective polarization, whereas far-right attacks depolarize the electorate. We provide evidence that this discrepancy can partly be explained by the perceived salience of attacks and different attitudes towards contentious and polarizing issues.