NCJ Number
226840
Journal
Problems of Forensic Sciences Volume: 69 Dated: 2007 Pages: 30-36
Date Published
2007
Length
7 pages
Annotation
This research determined whether the handwriting of monozygotic (MZ or identical) twins has more similarities than the handwriting of dizygotic (DZ or fraternal) twins, as well as the distribution of common graphic features in each of these groups.
Abstract
The study found that in the samples of both types of twins, differences in handwriting features predominated over similarities. In the comparison of the handwritings of the samples of identical and fraternal twins, however, the predominance of differences was slightly less for identical twins. None of the examined handwriting features was rated as similar significantly more often for identical twins than fraternal twins. The analysis was conducted on handwriting and signature samples submitted by 54 pairs of twins, including 31 pairs of MZ and 23 pairs of DZ twins. Each twin wrote a short text that contained all the letters of the alphabet, and each submitted specimens of his/her usual signature. The analysis of the writing and signature samples took into account 32 features. Each feature’s degree of similarity was rated by two experts independently using a four-grade scale. In comparing each feature for each pair of twins, the assigned conclusion was one of the following: “definitely different,” “rather different,” “rather similar,” and “definitely similar.” In analyzing the assessment results, an appropriate numerical value was ascribed to each category. Averages were calculated in defining the degree of similarity of handwriting within each twin pair. Averages were also used to define the degree of similarity for each of the 32 features of the handwriting for all the pairs. 10 figures and 8 references