President Donald Trump has spent years calling his opponents crooked, stupid and criminal. His niece, Mary Trump, says those insults tell you more about him than about them.

Mary Trump is a clinical psychologist and the author of a bestselling book about her family. In her Friday newsletter, she wrote that “every accusation Donald makes is really a confession.”

“When Donald says that somebody is stupid, has a low IQ, or is corrupt, criminal, or traitorous, he is literally talking about himself,” she wrote. “He just isn’t aware of it because acknowledging those shortcomings in himself is unthinkable to him.”

She said this is projection, a common defense mechanism in which people pin traits they can’t accept in themselves on someone else. It isn’t the same as hypocrisy, she added, because it usually happens “outside of conscious awareness.”

“To acknowledge them would be to admit that he is nothing he claims to be: smart, strong, sophisticated, and successful,” she wrote.

She traced the habit back to her grandfather, Fred Trump, who she said split the world into winners and losers. He had “deep seated contempt” for people he saw as losers, she wrote, and her own father was one of them. Fred Trump Jr. died in 1981 at 42.

Donald learned early to bury any sign of weakness, she wrote, because showing it “could get him literally and metaphorically killed, because that is exactly what he watched happen to my dad.”

Mary Trump said the pattern shows up in Trump’s refusal to accept his 2020 loss and in his repeated calls to jail political rivals. Those rivals include former special counsel Jack Smith, Hillary Clinton, Joe Biden, Barack Obama and New York Attorney General Letitia James.

“Donald, stop looking in a mirror when you say these things,” she wrote.

She said that when Trump himself faces investigations, “it’s the investigators who are criminals.”

“Donald can never be the bad guy in his own mind,” she wrote. “He is full of grievance. He is the perpetual victim, and the rest of us can never, ever, ever be allowed to forget it.”

She said Trump isn’t really trying to win the country over to what she called his “delusional framework.”

“He is really just trying to convince himself,” she wrote.