Trump, we are told, processes information orally. If you process information orally, you likely process little information. And if you process little information, you exude even less. Every time Trump comments on a subject, he reveals how little he knows about it. He wondered aloud why the Civil War was fought. He said he’s been treated worse than Abraham Lincoln, who was assassinated. He didn’t know what happened at Pearl Harbor. He’s too dumb to know he’s ignorant, and he’s too narcissistic to care.

As John McWhorter, a linguistics professor at Columbia University, observed, oral communication is personal, focuses on emotions, and “reinforces what you know,” whereas the written word “collects information we don’t memorize.” The latter is conducive to prolonged thinking.

Trump, putative author of three books with “think” in the title, doesn’t like to think. He doesn’t even think about himself — his favorite subject — much less about public health. He lives and acts in the moment, chasing instant gratification, which reading does not provide. That’s why he prefers television and Twitter to reading and thinking: they are immediate, visceral, and cognitively undemanding.