Submission status
Reviewing
Submission Editor
Noah Carl
Title
International meta-analysis of dysgenic fertility for intelligence
Abstract
Research on the relationship between fertility and intelligence, while extensive, is mostly limited to the United States.The existence and magnitude of dysgenic fertility could vary depending on the region and the country; however, this area of research has not been explored. To overcome this limitation, the magnitude of dysgenic fertility for intelligence in 65 different countries was calculated by consulting the literature and analyzing international datasets (n = 419,444, k = 156), as well as the magnitude of the correlation between fertility and educational attainment (n = 797,455, k = 454). Based on the results of the meta-analysis, the average country’s IQ is declining by 0.35 points per decade. Region comparisons suggest that the relationship between the number of children and intelligence is strongest in Latin America, Iran, and Turkey. In Denmark, Iceland, Estonia, Finland, and Switzerland, intelligence and fertility are negligibly related. However, there were some concerns with the quality of the international data which put the latter finding in question.
The magnitude of the decline in IQ globally is about 1.1 point per decade between the years of 2023 and 2100, though the rate at which intelligence is declining is falling. When weighted by population, the magnitude of the decline within countries is 0.4 points per decade, so 36% of the global decline in IQ is within countries. National IQ and the selection differential for IQ correlates at 0.51, while socioeconomic development and the selection differential for IQ correlates at 0.48.
Keywords
intelligence,
IQ,
meta-analysis,
international,
fertility
Supplemental materials link
https://osf.io/2fb4p/
Reviewer 1: Considering / Revise
Reviewer 3: Accept
Reviewer 4: Accept
