Retweet for justice? Social media message amplification and Black Lives Matter allyship

White allies can advance racial justice on social media by amplifying Black activists and educating their White friends. Social media platforms like Twitter and Instagram have different affordances for message amplification, with some showcasing the message creator and others the message amplifier. How might these visibility differences influence the reception of a message created by a Black activist and amplified by a White ally? Two online experiments (N1 = 328, N2 = 328) of White participants found that affordances prioritizing the White message amplifier over the Black message creator led to reduced perceptions of messenger racism when the message was holding White people accountable for the maintenance of racism. However, participants in these conditions also had a harder time identifying that the message creator was indeed a Black activist. These results demonstrate the important nuances of social identity and allyship effects in the context of social media affordances.