Study of Signatures Written over Extended Periods of Time*

One of the basic premises of forensic handwriting examination is that a person’s writing may gradually change over time. While handwriting change is frequently evident to varying degrees, it is not known how reliably, and to what degree, change occurs.
The current study was conducted on the normal course of business signatures of 51 individuals, written over an average of four decades, in order to determine whether specific aspects of handwriting change over time. The research showed that, based on the eight characteristics defined by the authors, most individuals’ handwriting changes very little over time, and that the most common change in writing occurs in line quality at an average age of 77 years. While limitations are noted in the research methods and materials, the size of the research sample provides a substantive foundation for continuing research on this topic.