Complexity in genuine signatures versus forged signatures: myth or reality

Handwriting is a complex neuromuscular activity, with writing complexity being one of the key features impacting the ease of imitation. Generally, higher complexity signatures are more difficult to replicate without revealing signs of simulation. However, some low-complexity signatures can be harder to simulate, suggesting unexplored factors influencing complexity. This study aimed to differentiate between genuine and simulated pen-paper signatures across various styles by examining handwriting characteristics, including absolute size, slant, lateral expansion, and the number of pen lifts. Signature complexity is often believed to correlate with forgery difficulty, yet existing literature presents conflicting evidence. By analyzing different signature styles and their characteristics, this study sought to enhance understanding of the factors influencing signature imitation. Findings confirmed that pen lifts are not significant indicators for distinguishing between genuine and simulated signatures in text-based and non-complex stylized categories. Complexity features, such as the number of turning points and line intersections, provided more reliable differentiation. Higher complexity scores were associated with genuine signatures, while simulated signatures typically exhibited fewer turning points and intersections. This study indicated a potential for further research to uncover additional factors affecting signature complexity and imitation, ultimately contributing to more effective forensic examination practices.