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Index and ring finger ratio--a morphologic sex determinant in South-Indian children

Tanuj Kanchan1, G Pradeep Kumar

  • 1Department of Forensic Medicine and Toxicology, Kasturba Medical College (Affiliated to Manipal University), Mangalore, India. tanujkanchan@yahoo.co.in

Forensic Science, Medicine, and Pathology
|April 7, 2010
PubMed

Insights

The index and ring finger ratio can distinguish between male and female South Indian children aged 2-12. A ratio below 0.97 suggests male, while above 0.97 indicates female, regardless of age.

Area of Science:

  • Anthropology
  • Human biology
  • Forensic science

Background:

  • Sexual dimorphism in anthropometric traits is well-documented.
  • The 2D:4D ratio (index to ring finger length) is a recognized marker of prenatal hormone exposure and potential sex differences.
  • Limited research exists on this ratio in South Indian pediatric populations.

Purpose of the Study:

  • To investigate the sexual dimorphism of the index and ring finger ratio (2D:4D) in South Indian children.
  • To determine if the 2D:4D ratio can serve as a reliable sex indicator in this demographic.
  • To explore correlations between the 2D:4D ratio, age, and finger lengths.

Main Methods:

  • Measurement of index finger length (IFL) and ring finger length (RFL) in 350 South Indian children aged 2-12 years.
  • Calculation of the 2D:4D ratio by dividing IFL by RFL.
  • Statistical analysis using SPSS version 11.0 to compare ratios between sexes and correlate with age.

Main Results:

  • Mean RFL was greater than mean IFL in both sexes.
  • While mean RFL was longer in males and mean IFL longer in females, these differences were not statistically significant.
  • A statistically significant difference was observed in the 2D:4D ratio between males and females, with females exhibiting a higher ratio.
  • The 2D:4D ratio showed no significant correlation with age.

Conclusions:

  • The index and ring finger ratio demonstrates significant sexual dimorphism in South Indian children.
  • A 2D:4D ratio of 0.97 or less is indicative of a male, and a ratio greater than 0.97 suggests a female.
  • The 2D:4D ratio is a potentially useful, age-independent sex indicator in this population.

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