Radiographic digit ratios (2D:4D) of Afro-Caribbean children: Comparisons with published data from white children

• Published in: Early human development Vol. 146; p. 105072
• Main Authors: Trivers, R., Jacobson, A., Manning, J.T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2020
• Subjects: Children; Ethnicity; Radiographic 2D:4D; Sex differences; Radiographic 2D:4D; Sex differences; Ethnicity; Children
• ISSN: 0378-3782; 1872-6232
• DOI: 10.1016/j.earlhumdev.2020.105072

Digit ratio (2D:4D) from soft-tissue measurements of fingers from children and adults from Black and White ethnic groups show sex differences (males<females) and group differences (Black< White). However, less is known about such differences in radiographic 2D:4D. To consider sex and ethnic differences in radiographic 2D:4D of children of Afro-Caribbean descent and to compare these means with “standards” from White children. A cross-sectional design with samples from Afro-Caribbean children aged 6 to 11 years compared to published radiographic measurements for White children in the Fels Longitudinal Study. Radiographic 2D:4D showed ethnic differences such that Afro-Caribbeans<Whites. There was an age-stable right-side sex difference (boys<girls) in the 2D:4D of the distal phalanx and the distal soft-tissue tip in the Afro-Caribbean children but not in the proximal- and middle-phalanges or the composite length of the phalanges. Sex differences in 2D:4D (boys<girls) were present in the White children in the middle and proximal phalanges and composite phalange length but not in the distal phalanx. In Afro-Caribbean children, mean radiographic 2D:4D was lower than that of White children and sexual dimorphism of 2D:4D (boys<girls) was confined to the distal phalanx and fingertip soft-tissue. In contrast in White children, there were no sex differences in the distal phalanx but there were in the middle-, proximal and composite phalanges (boys<girls). We discuss whether these differences in 2D:4D are widespread among Blacks and Whites and the implications for the interpretation of radiographic 2D:4D and morphological soft-tissue 2D:4D across macro-ethnic groups. •We considered 2D:4D sex differences in radiographic hand images in Afro-Caribbean children from Jamaica.•Sex differences (boys<girls) were found in the distal phalanx and the soft-tissue tip of the digit.•There were no sex differences in the proximal and middle phalanges or in the composite measure of all three phalanges.•White children show sex differences (boys<girls) in the proximal and middle phalanges and the composite of all phalanges.