A pair of studies published Thursday in the journal Science offers evidence not only that misinformation on social media changes minds, but that a small group of committed “supersharers,” predominately older Republican women, were responsible for the vast majority of the “fake news” in the period looked at. The studies, by researchers at MIT, Ben-Gurion University, Cambridge and Northeastern, were independently conducted but complement each other well. In the MIT study led by Jennifer Allen, the...