We examine how being single affects frustration and subsequent xenophobic behaviour. In a first step, we show that higher male-to-female ratios are associated with more anti-immigrant violence and far-right voting. We corroborate these correlations using an instrumental variables strategy exploiting the close-by availability of university places for females. Using simple experiments, we will test a behavioral mechanism underlying single men’s inclination to engage in anti-immigrant behaviour and political extremism. Single men perceive substantial social stigma of being single, which in turn, results in high levels of frustration. A simple informational intervention that corrects misperceptions about the stigma associated with being single, is meant to decrease frustration and look at the implications on attitudes towards immigrants.