R Trivers1, A Jacobson2, J T Manning3. 1. Biosocial Research Foundation, Southfield, St Elizabeth, Jamaica. 2. Department of Anthropology, Rutgers University, New Brunswick, NJ, USA. 3. Applied Sports, Technology, Exercise, and Medicine (A-STEM), Swansea University, Swansea, United Kingdom. Electronic address: j.manning@swansea.ac.
Abstract
BACKGROUND: 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. AIM: 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. SUBJECTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.
BACKGROUND: 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. AIM: 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. SUBJECTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.
Authors: Barbara Święchowicz; Anna Kasielska-Trojan; John T Manning; Bogusław Antoszewski Journal: Front Endocrinol (Lausanne) Date: 2022-06-30 Impact factor: 6.055