Recent Decline in Nonpaternity Rates: A Cross-Temporal Meta-Analysis
Bibliographic record
Abstract
Nonpaternity (i.e., discrepant biological versus social fatherhood) affects many issues of interests to psychologists, including familial dynamics, interpersonal relationships, sexuality, and fertility, and therefore represents an important topic for psychological research. The advent of modern contraceptive methods, particularly the market launch of the birth-control pill in the early 1960s and its increased use ever since, should have affected rates of nonpaternity (i.e., discrepant genetic and social fatherhood). This cross-temporal meta-analysis investigated whether there has been a recent decline in nonpaternity rates in the western industrialized nations. The eligible database comprised 32 published samples unbiased towards nonpaternity for which nonoverlapping data from more than 24,000 subjects from nine (mostly Anglo-Saxon heritage) countries with primarily Caucasian populations are reported. Publication years ranged from 1932 to 1999, and estimated years of the reported nonpaternity events (i.e., the temporal occurrence of nonpaternity) ranged from 1895 to 1993. In support of the hypothesis, weighted meta-regression models showed a significant decrease (r = -.41) of log-transformed nonpaternity rates with publication years and also a decrease, albeit not significant (r = -.17), with estimated years of nonpaternity events. These results transform into an estimated absolute decline in untransformed nonpaternity rates of 0.83% and 0.91% per decade, respectively. Across studies, the mean (and median) nonpaternity rate was 3.1% (2.1%). This estimate is consistent with estimates of 2 to 3% from recent reviews on the topic that were based on fewer primary studies. This estimate also rebuts the beliefs and hearsay data widespread among both the public and researchers which contend nonpaternity rates in modern populations might be as high as about 10%.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.025 | 0.045 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.007 | 0.031 |
| Bibliometrics | 0.004 | 0.006 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 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 source (direct Gemma or distilled Codex), 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".