“Kahan calls this theory “identity-protective cognition”: “As a way of avoiding dissonance and estrangement from valued groups, individuals subconsciously resist factual information that threatens their defining values.” Elsewhere, he puts it even more pithily: “What we believe about the facts,” he writes, “tells us who we are.” And the most important psychological imperative most of us have in a given day is protecting our idea of who we are and our relationships with the people we trust and love.”