Change of Second to Fourth Digit Ratio according to Age in Korean Children / 체질인류학회지

The 2nd to 4th digit ratio (2D : 4D) reflects exposure level of sex hormones in fetal period. The aim of this study is to identify a change of digit ratio according to age and a critical age showing gender difference in Korean children. This study was done on 1,182 children (588 males, 594 females). Data were collected by measuring index and ring finger length on both hands by photocopy. The data were analyzed using SPSS win 21.0. This study showed that the 2nd and 4th finger length and digit ratio of both hands increased with age both male and female. There was no differences in 2nd to 4th digit ratio between males and females until they were 3 years old. However, there were significant differences in 2nd to 4th digit ratio between males and females from the age of four. The results suggest that digit ratio in Korean children increases with age and a critical age showing gender difference is from the age of four.

Difference of Second to Fourth Digit Ratio according to the Methods of Measuring Length / 체질인류학회지

The 2nd to 4th digit ratio (2D : 4D) reflects exposure level of sex hormones in fetal period and there are various methods for finger length measurement. The aim of this study is to identify an accurate and effective method for finger length measurement. This study was done on 272 individuals (115 males, 157 females). Data were collected by measuring index and ring finger length on both hands by calipers, ruler, photocopy, and radiography. The data were analyzed through independent t-test, paired t-test, Pearson correlation analysis using SPSS win 19.0. This study showed that the 2nd and 4th finger measured by radiography were the longest finger both of males and females and revealed the largest length difference between 2nd and 4th finger. There were significant sex differences all of 4 measurement methods in 2D : 4D, especially remarkable sex difference by radiography and photography. The 2D : 4D by indirect measurement was lower than that of direct measurement. Correlation between digit ratio by radiography and by photocopy was 0.590 and correlation between digit ratio by radiography and by calipers was 0.586. The results of this study suggest that indirect measurement by radiography can be alternated by photocopy primarily and by calipers secondarily.

Second to Fourth Digit Ratio as a Sex Determinant in Korean / 체질인류학회지

The 2nd to 4th digit ratio (2D : 4D) as a predictor of the degree of expression of sexually dimorphic and other sex-hormone-mediated traits differs between the sexes, ethnics and race. The aim of this study is to identify characteristics and role of 2nd to 4th digit ratio as a sex determinant in Korean. This study was done on 664 individuals (332 males, 332 females). Data were collected by measuring index and ring finger length on both hands with digital callipers. The data were analyzed through the frequency, descriptive statistics, X2 test, independent t-test, paired t-test, Pearson correlation analysis using SPSS win 19.0. This study showed that the 2nd to 4th digit ratio (2D : 4D) in Korean men (0.96) was significantly lower than that of women (0.97). There was a significant difference in the types of 2nd and 4th finger length according to sex. There was a significant difference between right 2D : 4D and left 2D : 4D both of Korean men and women. Correlation between right and left hand digit ratio was .530 in men and .556 in women. The 2nd to 4th digit ratio accurately determinated sex in 89.1% males and 89.2% females for the left hand, and in 91.8% males and 91.9% females for the right hand. The results of this study suggest that 2nd to 4th digit ratio in Korean differs between males and females, moreover, it will be able to perform a role as a sex determinant.