Recent decline in nonpaternity rates: a cross-temporal meta-analysis

Area of Science:

• Psychology
• Sociology
• Genetics

Background:

• Nonpaternity, or discrepant biological versus social fatherhood, impacts familial dynamics, relationships, sexuality, and fertility.
• The widespread adoption of modern contraception, particularly the birth control pill since the 1960s, suggests a potential influence on nonpaternity rates.

Purpose of the Study:

• To investigate whether nonpaternity rates have recently declined in Western industrialized nations.
• To analyze trends in nonpaternity using a cross-temporal meta-analysis.

Main Methods:

• A meta-analysis of 32 published samples, comprising over 24,000 subjects from nine Western industrialized countries.
• Data spanned publication years from 1932 to 1999, with estimated nonpaternity events ranging from 1895 to 1993.
• Weighted meta-regression models were used to analyze the relationship between nonpaternity rates and time.

Main Results:

• A significant decrease in log-transformed nonpaternity rates was observed with increasing publication years (r = -.41).
• A non-significant decrease was also noted with estimated years of nonpaternity events (r = -0.17).
• Estimated absolute declines were 0.83% and 0.91% per decade, respectively, with a mean nonpaternity rate of 3.1% across studies.

Conclusions:

• The study supports the hypothesis of a recent decline in nonpaternity rates in Western industrialized nations.
• The findings contradict widespread beliefs of higher nonpaternity rates (around 10%) in modern populations.
• The average nonpaternity rate is estimated at 3.1%, aligning with recent reviews and indicating a significant historical decrease.