The theory of psychological essentialism provides an account of how and why some social groups are represented as if they possessed an inhering, immutable and group-defining ‘essence’. Whilst much of the empirical and theoretical work on essentialism has attended to characterising its cognitive components through the utilisation of survey measures, this article, adopting a synthetic discursive psychological approach, examines naturally-occurring conversations on talkback radio. We demonstrate how speakers attribute Sudanese refugees with essentialised cultural or tribal properties. These qualities were employed to account for the violent behaviour of Sudanese refugees, both in Sudan and in Australia, as relatively invariant and collectively shared attributes. Although participants recurrently depicted Sudanese refugees as sharing a cultural essence, these latent propensities were constructed to only manifest in the behaviour of some group members. We contend that essentialist ontologies can be established on implicit lay theories, causally linking culture to behaviour, and acting ideologically as rationalisations for illiberal and racist ends. We discuss how a discursive approach affords insights into the nuanced practice of psychological essentialism in everyday talk.