Study Refutes Alternative Theory on 2D:4D Ratio, Strengthens Link to Sex Hormones
A groundbreaking study published in Scientific Reports (DOI: 10.1038/s41598-021-87394-6) has challenged a long-standing theory about the 2D:4D ratio, the comparison of the lengths of the second and fourth fingers. Led by Dr. Svetlana Yuryevna Dronova of HSE University, the research involved a large-scale analysis of data from 7,500 people.
The 2D:4D ratio has been observed to differ between males and females, with males typically having a lower ratio. This difference has traditionally been attributed to varying levels of androgens and oestrogens. The ratio is considered a sexually dimorphic characteristic, influenced by both genetic and environmental factors. However, an alternative theory proposed that men's larger body parts, including fingers, might be the cause.
Dr. Dronova's study refuted this alternative theory. It found no correlation between total finger length and the 2D:4D ratio. Instead, the study supported the influence of sex hormones on the ratio. The sex differences in 2D:4D ratios were consistent across all nationalities and ages, while finger lengths varied between men and women. The 2D:4D ratio can now be used more confidently alongside other indicators to evaluate the risks of oestrogen abundance in embryos and potential health consequences.
The study, involving 7,500 participants, has strengthened the understanding of the 2D:4D ratio and its connection to sex hormones. It has refuted an alternative theory, paving the way for more accurate evaluations of oestrogen abundance and related health risks. The findings, published in Scientific Reports, contribute significantly to the understanding of human sexual dimorphism.
