Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations
Abstract Recently, a number of authors have claimed that sexual dimorphism in the second-to-fourth digit ratio (2D:4D) is simply dependent on digit length and is an artifact of allometry. The goal of our study is to verify the validity of these assumptions. The study sample comprised 7,582 individua...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2021-04-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-021-87394-6 |
| _version_ | 1818858338237022208 |
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| author | Marina Butovskaya Valentina Burkova Yulia Apalkova Daria Dronova Victoria Rostovtseva Dmitriy Karelin Ruzan Mkrtchyan Marina Negasheva Valery Batsevich |
| author_facet | Marina Butovskaya Valentina Burkova Yulia Apalkova Daria Dronova Victoria Rostovtseva Dmitriy Karelin Ruzan Mkrtchyan Marina Negasheva Valery Batsevich |
| author_sort | Marina Butovskaya |
| collection | DOAJ |
| description | Abstract Recently, a number of authors have claimed that sexual dimorphism in the second-to-fourth digit ratio (2D:4D) is simply dependent on digit length and is an artifact of allometry. The goal of our study is to verify the validity of these assumptions. The study sample comprised 7,582 individuals (3,802 men and 3,780 women) from three large world populations: Europeans (n = 3043), East Africans (n = 2844), and Central Asians (n = 1695). The lengths of the second and fourth digits on both hands were measured. Digit ratios were computed according to standard procedures. Analyses were conducted separately for each hand for the whole sample and in succession for the three large populations. Additionally, we separately tested four age cohorts (≤ 13, 14–18, 19–30, and 31 ≥ years) to test the effect of developmental allometry. The second and fourth digits showed strong positive linear relationships on both hands, and demonstrated an increase with age; digit length in women from the youngest age cohort was longer or equal to that of men, and shorter than men in older age cohorts. However, the 2D:4D magnitude and its sexual dimorphism remained stable throughout the ontogeny. To test for an allometric effect on 2D:4D, the average digit lengths were calculated. Both sex and population origin were permanent reliable predictors of 2D:4D, whereas average digit length was not. Height was applied as another measure of allometric effect on the limited sample (≤ 30 years) from the European population, along with sex and age. No allometric effect was observed in this case. We conclude that sex differences in 2D:4D are not an artifact of allometry. |
| first_indexed | 2024-12-19T08:54:42Z |
| format | Article |
| id | doaj.art-7b25489156c349b2b5fecbe7f80d9cde |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-19T08:54:42Z |
| publishDate | 2021-04-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-7b25489156c349b2b5fecbe7f80d9cde2022-12-21T20:28:39ZengNature PortfolioScientific Reports2045-23222021-04-0111111710.1038/s41598-021-87394-6Sex, population origin, age and average digit length as predictors of digit ratio in three large world populationsMarina Butovskaya0Valentina Burkova1Yulia Apalkova2Daria Dronova3Victoria Rostovtseva4Dmitriy Karelin5Ruzan Mkrtchyan6Marina Negasheva7Valery Batsevich8Institute of Ethnology and Anthropology, Russian Academy of SciencesInstitute of Ethnology and Anthropology, Russian Academy of SciencesInstitute of Ethnology and Anthropology, Russian Academy of SciencesInstitute of Ethnology and Anthropology, Russian Academy of SciencesInstitute of Ethnology and Anthropology, Russian Academy of SciencesInstitute of Geography, RASYerevan State UniversityMoscow State UniversityMoscow State UniversityAbstract Recently, a number of authors have claimed that sexual dimorphism in the second-to-fourth digit ratio (2D:4D) is simply dependent on digit length and is an artifact of allometry. The goal of our study is to verify the validity of these assumptions. The study sample comprised 7,582 individuals (3,802 men and 3,780 women) from three large world populations: Europeans (n = 3043), East Africans (n = 2844), and Central Asians (n = 1695). The lengths of the second and fourth digits on both hands were measured. Digit ratios were computed according to standard procedures. Analyses were conducted separately for each hand for the whole sample and in succession for the three large populations. Additionally, we separately tested four age cohorts (≤ 13, 14–18, 19–30, and 31 ≥ years) to test the effect of developmental allometry. The second and fourth digits showed strong positive linear relationships on both hands, and demonstrated an increase with age; digit length in women from the youngest age cohort was longer or equal to that of men, and shorter than men in older age cohorts. However, the 2D:4D magnitude and its sexual dimorphism remained stable throughout the ontogeny. To test for an allometric effect on 2D:4D, the average digit lengths were calculated. Both sex and population origin were permanent reliable predictors of 2D:4D, whereas average digit length was not. Height was applied as another measure of allometric effect on the limited sample (≤ 30 years) from the European population, along with sex and age. No allometric effect was observed in this case. We conclude that sex differences in 2D:4D are not an artifact of allometry.https://doi.org/10.1038/s41598-021-87394-6 |
| spellingShingle | Marina Butovskaya Valentina Burkova Yulia Apalkova Daria Dronova Victoria Rostovtseva Dmitriy Karelin Ruzan Mkrtchyan Marina Negasheva Valery Batsevich Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations Scientific Reports |
| title | Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations |
| title_full | Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations |
| title_fullStr | Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations |
| title_full_unstemmed | Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations |
| title_short | Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations |
| title_sort | sex population origin age and average digit length as predictors of digit ratio in three large world populations |
| url | https://doi.org/10.1038/s41598-021-87394-6 |
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