A sleekly designed poster has an authoritative voice. We’re culturally conditioned to listen up when we see nice fonts and well-placed wording. In the People’s Secret History: Group Show, which is coming to EM Wolfman Small Interest Bookstore (410 13th St., Oakland), artists leverage that aesthetic correspondence to legitimacy to amplify narratives from radical history that are often discredited. At this point, academic attention has been brought to the social underdog’s version of history — which would have been left out of textbooks in the past — but there are still many stories left unheard. Referring to these stories as “secret histories,” the artists in this group show are ready to reveal them in the form of informational posters — a style inspired by the Just Seeds Artists’ Cooperative poster series. Some of the featured stories challenge the dominant narrative of history to such an extent that they might even be deemed “conspiracy theories.” This show offers an opportunity to test to what extent perspectives that you might have questioned before become believable when presented with ad-like aesthetics. There will be an opening reception on August 6 at 7 p.m. with performances by Grey & Grey and Bad Carl Sagan.