Inbreeding depression is the reduced biological fitness in a given population as a result of inbreeding, or breeding of related individuals. Population biological fitness refers to an organism's ability to survive and perpetuate its genetic material. Inbreeding depression is often the result of a population bottleneck. In general, the higher the genetic variation or gene pool within a breeding population, the less likely it is to suffer from inbreeding depression.
https://en.wikipedia.org/wiki/Inbreeding_depression
Before 1900, the negroid, African population was in serious decline. They were not able to survive, feed themselves, build language or cooperate in a civilization without slavery and outside aid. Colonialism boosted these numbers.
Inbreeding depression and intelligence quotient among north Indian children
https://pubmed.ncbi.nlm.nih.gov/8240214/
https://archive.is/cKmwD
A significant (p 0.001) negative association was found between inbreeding and score on the Weschler Intelligence Scale for Children (WISC-C). In addition, the weighted mean IQ of inbred children )88.4 + or - 1.37) differed significant (p 0.001) from that recorded among 50 noninbred controls of similar age and socioeconomic status (99.6 + or - 2.0). The group means for both verbal and performance IQ subscales differed significantly and in the expected direction between subjects and controls
Inbreeding depression and IQ in a study of 72 countries
https://www.sciencedirect.com/science/article/abs/pii/S0160289608001608
https://archive.is/AimUB
In this ecological study, a robust negative correlation of r = − .62 (P < .01) is reported between national IQs and consanguinity as measured by the log10 transformed percentage of consanguineous marriages for 72 countries.
This correlation is reduced in magnitude, when IQ is controlled for GDP per capita
Except that higher GDP nations are filled with Europeans or were built by Europeans, a minority group on Earth... and Asians. So this proves that there is inbreeding depression in the Negro, Arab, Indian and Native-American. Assuming we place GDP and intelligence together. Which they did. And forgot they were proving the opposite of what they concluded.
Fertility is generally lower among racially exogamous than endogamous unions, especially among Asian American-White couples.
https://onlinelibrary.wiley.com/doi/abs/10.1111/jomf.12758
For all those yellow fever people who think mixing Asians with Europeans is a great thing. It's not.
Interracial Couples Have Lower Fertility Rates on Average, Qian Finds
The study also found that fertility patterns vary between racial pairings, with particularly low rates found among Asian American-White couples and comparatively higher rates for American Indian-White couples. These rates also varied by gender, with White male/Black female and White male/Hispanic female couples following the fertility patterns of White couples, and Black male/White female couples and Hispanic male/White female couples following the fertility patterns of endogamous Black and Hispanic couples respectively.
The male determines interracial birth rates. It's important for men to understand that breeding is up to them. Make the right decision.
https://www.brown.edu/academics/population-studies/news/article/2021/interracial-couples-have-lower-fertility-rates-average-qian-finds
(post is archived)