Researchers at the Robert H Smith School of Business at the University of Maryland measured the signatures of 650 CEOs on 10 years’ worth of annual reports from almost 400 top 500 companies.
Large signatures, which have been linked to narcissistic personality traits such as dominance and an outsize ego, were positively associated with overspending, lower return on assets, but higher CEO pay relative to other industry peers.
The companies of these CEOs spend more on capital goods and acquisitions but had worse sales and sales growth over several years. They also had fewer patents suggesting a lack of innovation.
This is probably because narcissistic leaders dominate discussions, ignore criticism and belittle other employees.
The assumption about big signatures and narcissism is based on research by Richard Zweigenhaft which showed that people with higher self-esteem and more dominant personalities had large signatures.
It’s also the case that the CEO population is more narcissistic than the general population as well as having other dark triad characteristics.
Source: HBR May 2013