Immigration, cultural diversity and integration are among the most central challenges for modern societies. Integration is often impeded by negative emotions and prejudices held by the majority members towards immigrants in a common society. Based on the ingroup projection model (Mummendey & Wenzel, 1999), we examined the impact of perceived relative ingroup prototypicality on intergroup emotions and prejudice. Additionally, we examined whether this impact is causal and explored the issue of causality in more detail contrasting a linear causal model with bi-directional or reciprocal causality. Hypotheses were tested in a study with a two-wave panel of majority members (N=1085) in Germany. We examined the proposed relations between relative ingroup prototypicality, intergroup emotions and prejudice and determined the causal direction of these relationships. Results support the predictive power of relative ingroup prototypicality on intergroup emotions and prejudice. Moreover, most causal relations between our measures are reciprocally causal. We discuss the implications of these findings for the general conception of prejudice and intergroup emotions.