A formidable empirical literature describes loneliness as a perceived deficiency in social connection and inclusion associated with a range of mental and physical health problems and multiple maladaptive coping strategies. Many of these negative consequences can be accounted for by Cacioppo, Cacioppo, and Boomsma's evolutionary theory of loneliness, which reasons that a lack of adequate interpersonal connection is aversive because, evolutionarily, such a detriment posed threats to the ability of individuals to survive and reproduce. The theory proposes that loneliness therefore produces feelings of heightened anxiety and perceptions of vulnerability to threat that motivate individuals to attend to their relational needs. In modernity, heightened anxiety and perceptions of threat also correspond to politically conservative ideologies, such as a fear of foreigners (xenophobia), a preference for authoritarianism, and a lack of tolerance for distress. Working from the premise of Cacioppo's theory, the present study therefore reasoned that loneliness is associated with endorsement of such politically conservative values. A nationwide survey of 848 American adults confirmed that loneliness is positively correlated with xenophobia and endorsement of right-wing authoritarianism and negatively associated with distress tolerance.