Inbreeding is associated with lower 2D: 4D digit ratio
Bibliographic record
Abstract
OBJECTIVES: While consanguineous marriage has been shown to result in a small increase in risk of recessive Mendelian disorders among offspring, far less research has been conducted on the effects of inbreeding on complex traits. These effects, thought to result from increased developmental instability due to loss of heterozygosity, are expected to be found more pervasively than rare recessive Mendelian traits and are expected to result in increased developmental noise. Here, we test for a direct effect of inbreeding on 2D : 4D, a putative indicator of prenatal hormonal environment. METHODS: We compared the 2D : 4D ratios of 122 male and 108 female consanguineous (children of first cousin marriages) high school and university students to those of 142 male and 122 females controls. RESULTS: Across hands and sex, consanguineous parentage was consistently associated with lower, more masculine-typical, digit ratios. Digit ratios were 1.3-1.9 times more variable among the consanguineous group than the control group. While socio-economic status cannot explain the effects seen in our data, we found that lower, more masculinized, digit ratios were associated with lower family income. CONCLUSIONS: Our results suggest that consanguineous marriages are associated with a fetal environment that influences morphological development and may have associated behavioral sequelae.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".