Critical Discourse Analysis has identified a number of (fallacious) argumentation schemes that reoccur in anti-immigration discourse and which serve strategically to legitimise restrictive immigration policies. In this paper, I argue that the move from the premise to the presupposed conclusion which realises such argumentation strategies in fact reflects adapted decision rules operationalised by a so called ‘cheater-detection’ module (Cosmides 1989). On this account, assertions in anti-immigration discourse provide the necessary input to the cheater-detection module to result in decisions in favour of discriminatory policies and practices. Persuasion, or perhaps even manipulation, is then not a matter of pragmatic reasoning processes but may instead involve the exploitation of evolved cognitive programmes. I show how assertions in anti-immigration discourse activate the cheater-detection module in a critical analysis of representations of immigrants and asylum-seekers in the British right-wing press.