The discovery that linked signature size to narcissism

Researchers have used signature size to explore narcissism in CEOs and other senior corporate positions.

For years, Donald Trump’s distinctive, large, and bold signature has captured the public’s attention. Not only did it recently come to light that his signature appeared in a book that Jeffrey Epstein received for his 50th birthday, but it fits neatly alongside Trump’s long history of brash self-adulation. “I love my signature, I really do,” he said in a September 30, 2025, speech to military leaders. “Everyone loves my signature.”