We propose a general hypothesis that integrates affective and cognitive processing with neuroanatomy to explain anxiety pronenes. The premise is that individuals who are prone to anxiety show an altered interoceptive prediction signal, i.e., manifest augmented detection of the difference between the observed and expected body state. As a consequence, the increased prediction signal of a prospective aversive body state triggers an increase in anxious affect, worrisome thoughts and other avoidance behaviors. The anterior insula is proposed to play a key role in this process. Further testing of this model--which should include investigation of genetic and environmental influences--may lead to the development of novel treatments that attenuate this altered interoceptive prediction signal in patients with anxiety disorders.