Saeed Ghorbani - Assistant Professor, Department of Physical Education and Sport Science, Aliabad Katoul Branch, Islamic Azad University, Aliabad Katoul, Iran .
Ahdiyeh Yadolahzadeh - Assistant Professor, Department of Physical Education, Farhangian University, Tehran, Iran.
Masoud Shakki - MSc, Department of Physical Education and Sport Science, Aliabad Katoul Branch, Islamic Azad University, Aliabad Katoul, Iran.
Saharnaz Noohpisheh - MD, Department of Physical Education and Sport Science, Aliabad Katoul Branch, Islamic Azad University, Aliabad Katoul, Iran.

Background Genetic impacts on handwriting legibility and speed, especially in early childhood, are not well understood. The present study used a ۲D:۴D ratio as a biological marker to investigate the associations between genetic factors with quality and speed of handwriting among the elementary school children. Materials and Methods: The present study used a comparative-correlational method. Participants included ۱۰۹ boys and ۱۱۴ girls attending second and third grades in regular elementary schools in ۲۰۱۹ in Golestan province, Iran. The Persian Handwriting Assessment Tool (Havaei et al. ۲۰۱۷), and photocopy method were used to measure handwriting performance and ۲D:۴D ratio, respectively. Legibility in copying and dictation, as well as the speed of handwriting, were assessed as dependent variables. Results: The results showed that boys and girls had identical age and education. Moreover, it was revealed that boys had significantly lower ۲D:۴D ratio in both right and left hands compared to girls (P<.۰۰۱). Furthermore, a negative association was observed between right ۲D:۴D ratio with word space in copying (r=-.۲۳, P<.۰۰۱) as well as a significant positive association between left ۲D:۴D ratio with word formation (r=.۱۳, P=.۰۴) in the dictation of boys. Additionally, the results indicated a significant negative association between right ۲D:۴D ratio with word alignment in the dictation of girls (r=-.۲۰, P=.۰۲). No other significant associations were observed between ۲D:۴D ratio and handwriting performance. Finally, no significant differences were observed between boys and girls in handwriting performance. Conclusion According to the results, the ۲D:۴D ratio does not positively affect handwriting quality and speed in elementary school children.

Digit ratio, handwriting, legibility, speed