Fingerprint pattern distributions under the Vucetich and Henry systems: A large-scale statistical assessment with...

This study presents a comprehensive statistical analysis of fingerprint general patterns in a Brazilian dataset of more than 500,000 individuals. Using both the Vucetich and Henry systems, we examined the distribution of arches, whorls, internal/external loops, and ulnar/radial loops across finger type, sex, and geographic origin. Chi-square tests, non-parametric methods, effect size metrics, and Z-tests for proportions were applied, together with cross-national comparisons using large datasets from the United States (FBI/NIST) and the Netherlands. The results demonstrate that finger type emerged as the dominant factor associated with general pattern distribution, explaining the vast majority of the observed variance in both classification frameworks. Sex and geographic origin produced statistically significant but weak effects, detectable primarily due to the large sample size. Finger-specific patterning showed strong bilateral coherence and remarkable stability, reinforcing the developmental robustness of Level 1 details. Cross-national comparisons revealed highly similar distributional structures among Brazilian, American, and Dutch samples, with comparable trends also observed in smaller datasets from Sweden, Algeria, and Spain. Overall, the findings demonstrate that friction ridge general patterns provide both a stable basis for forensic identification and a sensitive, though subtle, indicator of population structure when extremely large datasets are available. Taken together, these results highlight that anatomical determinants overwhelmingly shape pattern distribution, whereas demographic influences-although statistically detectable-are consistently small in practical magnitude. This dual structure underscores the simultaneous forensic reliability and anthropological sensitivity of Level 1 details, reinforcing their applicability across jurisdictions and classification systems.