“…Based on this research, argumentation, and validation, many researchers have followed the approach of using signature sizes as a measurement of narcissism (e.g., Aabo et al, 2020;Chen et al, 2021;Chou et al, 2021;Ham et al, 2017Ham et al, , 2018Takada et al, 2021;Zhou, 2017), showing that signature size has become a widely accepted unobtrusive indicator for narcissism research. Even though signature measurement cannot cover all facets of narcissism (Karami, 2017), a number of its traits correlate positively with signature sizes, resulting in a greater likelihood of discovering a narcissist truthfully via their signature.…”