AbstractMedia stories often reach citizens via a two-step process, transmitted to them indirectly via their social networks. Why are some media stories strongly transmitted and impact opinions powerfully in this two-step flow while others quickly perish? Integrating classical research on the two-step flow of political communication and novel theories from cognitive psychology, this article outlines a model for understanding the strength of political frames in the two-step flow. It argues that frames that resonate with cognitive biases (that is, deep-seated psychological decision rules) will be transmitted more and have a stronger influence on opinion when citizens recollect media frames in their social networks. Focusing on the case of episodic and thematic frames, the study tests this model. It introduces a novel research design: implementing the children’s game ‘Telephone’ in consecutive experimental online surveys fielded to nationally representative samples. This design helps gauge the reliability of transmission and the degree of persuasiveness in actual chains of transmission.