For years, Donald Trump’s distinctive, large and bold signature has captured the public’s attention. Not only was it recently revealed that his signature appeared in a book Jeffrey Epstein received for his 50th birthday, but it sits well alongside Trump’s long history of brazen self-aggrandizement. “I love my signature, I really do,” he said in a Sept. 30, 2025, speech to military leaders. “Everyone loves my signature.”
His signature is also of interest to me given my decades-long fascination with the relationship between signature size and personal characteristics, and my occasional academic research.
A longtime social psychologist who has studied America’s elite, I made an unintended empirical discovery more than 50 years ago as an undergraduate.
The link I found at the time – and has been replicated by numerous studies since – is that signature size is related to a person’s mood and sense of self.
Signature size and self-esteem
In 1967, during my senior year of college, I was a student worker in the psychology library at Wesleyan University. My job, four nights a week, was to check out the books and shelve the books that were returned.
As students or faculty checked out the books, they were asked to sign their name on an orange, unlined card found in each book.
At some point I noticed a pattern: when professors signed books, they used a lot of space to sign their names. When students reviewed them, they used very little space, leaving plenty of room for future readers.
So I decided to study my observations systematically.
I collected at least 10 signatures for each faculty member and compared samples of student signatures with the same number of letters in their names. After measuring the amount of space used by height times width, I found that eight out of nine faculty members use more space to sign their names.
To test for age as well as status, I conducted another study in which I compared the signatures of blue-collar workers such as custodians and groundskeepers who worked at the school with a sample of faculty and a sample of students—again matched for letter count, this time on blank 3-by-5-inch cards. Blue-collar workers used more space than students but less than professors. I’ve come to the conclusion that age is at play, but so is condition.
About the author
Richie Zweigenhoft is professor emeritus of psychology at Guilford College.
This article was first published by The Conversation and is republished under a Creative Commons license. Read the original article.
When I told psychologist Carl Scheib, my favorite teacher, about my findings, he said I could measure his book signings, which he had signed for more than a decade since his freshman year of college.
As can be seen in the chart, his book signatures have mostly gotten bigger. They had a big jump from freshman to senior year, shrank a bit when he entered graduate school, and then increased in size as he finished his Ph.D. and joined the Wesleyan College.
I did a few more studies and published a few papers and concluded that signature size is related to self-esteem and a measure of what I call “status awareness.” I found that this pattern exists in different environments, including in Iran – where people write from right to left.
Narcissistic communication
Although my subsequent research included a book on CEOs of Fortune 500 companies, it never occurred to me to look at the signatures of these CEOs.
However, it occurred to some researchers 40 years later. In May 2013, I got a call from the editor of the Harvard Business Review because of the work I had done on signature sizes. They planned to interview Nick Seibert, an associate professor of accounting at the University of Maryland, about the potential link between signature size and narcissism in CEOs.
While Siebert told me that his research found no direct evidence for a positive relationship between the two, I was nevertheless intrigued by the possibility of a connection he inferred.
So I decided to test this using a sample of my students. I asked them to sign a white 3 by 5 card as if they were writing a check, and then I gave them the widely used 16-item scale of narcissism.
See, Siebert was right to infer a link: there was a significant positive correlation between signature size and narcissism. Although my sample size was small, this link subsequently led Seibert to test two different samples of his students. And he found the same significant and positive correlation.
Others soon began using signature size to assess narcissism in CEOs. By 2020, growing interest in the topic led the Journal of Management to publish an article that included signature size as one of five methods for measuring narcissism in CEOs.
A growing field
Now, almost six years later, researchers have used signature measurements to detect narcissism in CEOs and other senior corporate positions, such as CFOs. This link has been found not only in the United States, but also in countries including the United Kingdom, Germany, Uruguay, Iran, South Africa, and China.
Additionally, some researchers have studied the effect of larger versus smaller signatures on viewers. For example, in a recent article in the Journal of Philanthropy, Canadian researchers reported on three studies that systematically varied the size of a donor’s signature to see if it affected the size of the donation. did In one of their studies, they found that increasing the size of a sender’s signature generated more than twice as much revenue.
The surprising resurgence of research using signature size to assess narcissism leads me to several conclusions.
For example, signature size is much more powerful as a measure of certain aspects of personality than it was when I was a bright student working in a college library in 1967.
In fact, as I once came to the conclusion, the size of the signature is not the only indicator of status and self-esteem. It’s also, as recent studies show, indicative of narcissistic tendencies — the kind that many argue is exhibited by Trump’s big, bold signature.
Where this research goes next is anyone’s guess, least of all for someone who noticed something interesting about signature sizes years ago.
