An online experiment involving 251 Singaporeans assessed how social media influencers' (SMIs) prototypicality (i.e., embodiment of group attitudes) and social attraction affected their popularization of nuclear energy development. Participants exposed to a SMI with high prototypicality perceived the YouTube video more favorably, displayed greater intention to share the YouTube video, and possessed greater attitude intensity toward nuclear energy development. Participants displayed greater intention to share the YouTube video when the SMI had high social attraction and possessed moderate to high prototypicality. Conversely, participants displayed less intention to share the YouTube video when the SMI had low social attraction and prototypicality.