ABSTRACT
The aim of this study is to provide basic data to prevent adolescent crime or violence by analyzing aggression according to second digit to fourth digit ratio (2D : 4D). Index and ring finger length on both hands by photocopy was measured using Callipers from ventral proximal crease to finger tip. This study was done on 187 elementary school students (98 males, 89 females). Data were collected by measuring index and ring finger length on both hands by photocopy and by completing self-reported questionnaire. The data were analyzed using SPSS win 21.0. This study showed that the 2D : 4D of males was significantly lower than female, and the aggression score of males was significantly higher than female. Especially, there was significantly differences between 0.900 or less than 0.900 digit ratio group and 1.000 or more than 1.000 digit ratio group only left hand of males. The results of this study suggest that left digit ratio of males in elementary school students are able to be used as one of physical markers to evaluate aggression.