Adoption Studies and the hereditarian hypothesis: Part 1

 

Adoption studies are some of the best ways of finding out whether racial differences in intelligence are mainly due to genes or environment. Today I'll go over the Black transracial adoption studies as well as the studies of illegitimate mixed children, their findings and how they deal a major blow to race realism.

Transracial adoption studies

1. Scarr and Weinberg (et al) (1976,1992)

This is probably one of the most cited pieces of evidence in this debate by hereditarians. This is because it almost perfectly confirms the hereditarian hypothesis as opposed to the other more humbling results of other adoption studies. It is also known as the "Minnesota Transracial adoption study". It studied black, white, Asian, Amerindian, and mixed-race black/white children adopted by upper-middle-class white families in MN. The average IQ of the adopting parents was more than 1 SD above the population mean of 100. The biological children of these parents were also tested. The sample of adopted children was selected by eligible parents contacting the researchers for participating following a newsletter call. The IQ scores of non-adopted whites was collected. The results of the initial study (1976) were as follows:

figure 1

As we can see the racial IQ gap between the adopted whites and blacks (about 15 points) was the same as that of black and whites at the time in the general population. However there is barely any gap between Mullatos and Whites. However the shocking results of the study are revealed in the follow up study from 1992, to monitor the IQs of participants into adulthood. The results are again shown below:

figure 2

The gap between Whites and Mullatos widens significantly in the follow-up study. In the initial study the gap between Whites and Mullatos was just 2.5 points however it widened to 7 points. Same thing for Blacks. The gap between Whites and Blacks widened from 14.7 points to about 17 points. Even larger than the observed gap of 15 points seen outside of adoption studies. This almost perfectly supports the race realist perspective as it follows the hierarchy one would expect if racial IQ differences were genetic. Whites on top, Blacks at the bottom and Mullatos dead in the middle as white ancestry would predict one's IQ score. But what exactly is going on here? 

When we control for attrition a much fuller picture is painted. What exactly is attrition you may be wondering? Well attrition is simply the people who were "lost" and not able to participate in the follow up study.  The white children who were lost to attrition were relatively low in IQ compared to other members of their group. Of the initial 25 white adoptees, 9 were lost to attrition and they were disproportionately low IQ (relative to the white group). As Drew Thomas states in his paper (from which I get a massive amount of analysis in this post) "Racial IQ Differences among Transracial Adoptees: Fact or Artifact?"

"The lost adoptees had relatively low IQs, so the remaining White adoptees were unrepresentatively high in IQ, as Mackintosh observed. One can prove this by comparing the original IQs of the full sample and the subgroup who were measured at both ages 7 and 17; the latter subgroup had an initial mean IQ of 117.6 (with a minimum IQ of 92) but the full sample had an initial mean of 111.5 (minimum 62). Because initial and final IQs had a correlation of 0.63 among the White group, the elite subgroup would likely have had their final mean IQ inflated by about 0.63 × (117.6 − 111.5) = 3.8 points."

When a similar method is applied to the Blacks and Mullatos, we can effectively control for attrition in the 3 groups and see results which make more sense. 

Attrition deflated the Black IQ by only 0.7 IQ points and inflated the Mullato IQ by only 0.2 points. So controlling for attrition gives the following results:

figure 3

So it shows that the Black-white gap didn't actually widen at all. The Mullato-White IQ gap increased by 1 point from the initial study which is within the margin of error of 0.2 SD. The Black-white IQ gap narrowed from 14.7 IQ points in childhood to about  11.7 points at age 17. The mullato-white IQ gap is on average only 0.2 SD which can be attributed to statistical noise. What needs to be explained is the gap between the Black-White IQ gap in the study, which was about 13.4 IQ points on average, only 1.6 points smaller than the 15 point gap observed in wider society at the time. So why did the gap close significantly with Mullatos and not full Blacks?

Many factors easily explain this gap. The Black kids were adopted far later on average than the Mullatos by 2 years. This is because Black kids were almost certainly exposed to far worse pre-natal and post natal care including worse nutrition, lead poisoning, less breastfeeding etc. all correlated with lower IQ. It's important to note that these children were born in the late 60s just after the end of Jim Crow, at a time where Black people lived in far worse poverty and Black children were exposed to far worse care and environments. Furthermore the Black kids spent less time in their adoptive home (by 1.1 SDs); had more (by 0.4 SDs) and lower-quality (by 0.8 SDs) adoptive placements; and had adoptive parents with less education and lower mean IQ (by 0.2–0.3 SDs). Adoptive age  significantly predicted IQ in the study among adoptees. Early placed adoptees scored about 11 points higher than later-placed adoptees in the study as shown below. It's also important to note that these are the raw results (uncontrolled for attrition) and there are 3 results because the initial study gave the children IQ tests twice.  So all these factors explain the lower IQ scores of Black adoptees in the study. 

figure 4

2. Moore (1986)

This study compared Black children adopted by Black parents to Black and Mullato kids adopted by whites. The Black kids adopted by white parents scored almost 1 standard deviation higher (13 points) than Black kids adopted by Black parents. 

figure 5

This study is very important for 2 reasons because it contradicts many hereditarian talking points as European ancestry doesn't predict IQ here - Black kids score slightly higher than Mullatos and suggests the significant IQ differences between blacks raised by whites vs blacks raised by blacks suggests most of the racial IQ gap is due to socialization and environment.

3. Tizard et al (1972)

Tizard went to some Carribean countries and took the IQ scores of children in nursing homes, adopted homes and orphanages at very young ages. This study is very important as it takes place when the children are very young (average age- 4) and counters hereditarian narratives that a black-white IQ gaps already appearing at young ages are due to genes and not socialization

figure 6

In 2 of the studies there are no differences in IQ between the White, Black and Mullato Children. In the 3rd one where no fully Black kids take part, the Mullato children score 7 points higher than whites although they have a much smaller sample size.

Illegitimate Mixed Children

1. Eyferth (1961)

After world war 2 U.S soldiers deployed G.Is to garrison the occupied German zones. As usually happens when soldiers are deployed in foreign territory, the men have illegitimate children with local women. Eyferth contrasted the illegitmate children of Black G.Is with White G.Is and there were no racial IQ differences with White kids scoring 97.2 points and the Mullato kids scoring 96.5.

This is a great study as it had a decent sample size (N=251) and the mothers were of a similar socio-economic standing. 

This study clearly flies in the face of hereditarianism. How do they attempt to cope with this? With dishonest, low IQ tactics for a political agenda. The worst example of this comes from AltHype's article on this topic. Althype is where most of the amateur race realist dialogue tree comes from and is a prominent Hereditarian. He attempts to discredit this study using two "rebuttals"

1. He says that the selected Black population are cognitively selected because 30% of Black test takers were not allowed to join the military compared to 3% of whites due to lower IQ scores than the cut-off. This isn't surprising considering the lower rates of literacy and poorer schooling typical of Blacks during Jim Crow.

The graph above is Althype's graph illustrating this. Ignore him dubbing the soldiers "rapists".I could refute his "rapist" epithet but Brandolini's law comes to mind and that isn't the aim of this article today. This is nonsense not based in reality, it's important to note that Ryan Faulk (Alternative Hypothesis) is mentally retarded, he types this nonsense all from the comfort of his trailer park, slandering brave men who fought honourably in hostile, foreign lands. Meanwhile he is very emotional and cowardly and was very quick to block me on Twitter when his dogma is challenged. He's such an emotional baby lmao he's probably trying to be edgy here but his views are still important as many race realists get their views from him. 

Althype assumes that the average black IQ within WW2 draftees was 85 with a gap of 15 points with whites or one standard deviation for some reason, when in reality it was about 1.52 SD [Race Differences in Intelligence by Loehlin, Lindzey, and Spuhler (1975) page 143, table 6.2]. Here's Alt Hype's own graph from his article on the Black-White IQ gap:

 So that would mean the average IQ of the Black test taker during world war 2 was about 77.4 IQ points. So let's calculate the Black average when the bottom 30% is excluded. We do this by calculating the mean of the truncated bell curve which gives us a black average of 85 IQ points. Exactly the number Althype gives as the average for the wider Black population. For those interested in how I arrived at this I used R software to calculate the mean:

This is also shown by the fact that the bottom 3% of whites have a similar cut-off to the Black one (69.63), the bottom 3% of whites score 71.8 IQ points and below so our calculations are accurate. Therefore the Black GIs score a full standard deviation below the Whites yet their offspring have the same average IQ as that of the white GIs. This gives this new Bell curve for the Black GIs:

figure 7

How hereditarians can claim this is anything other than yet another refutation of their ideology is beyond me.

2. The second response is even more cope-y and pathetic. You see 20% of the kids tested were also illegitimate offspring of French Garrisons of North African origin. Hereditarians believes this somehow "raises" the Black IQ score because North Africans are "Caucasoids" Let's see Althype's explanation:

"In this study, however, “20 to 25 percent” of the “African” rapists were North African. Based on an estimate of Indians in the UK of 93, I we can conservatively estimate their IQ, – or at least their “genotypic IQ” – to be 93."

I am not making this up. He really said this. Here's the link. He uses the IQs of Indians in the UK to estimate the "genotypic" IQ of North Africans. It's also pivotal to also note that "genotypic" IQ doesn't exist and is a made up term by hereditarians. The tactic of using adjacent populations is something that Lynn does in his moronic work on national IQs which I will address in a later post but what is the basis for using Indians? Pakistanis are a geographically closer population to Arabs and have a more similar culture and religion. Even then, why use Indians in the UK, a clearly selected population, instead of India's national IQ? These French North Africans mostly didn't grow up in France but rather French Algeria/Tunisia/Morroco. Do you genuinely think Althype would use the average IQ of British-born Africans as their "genotypic" IQ? This is for dogmatic reasons. His aims here are to inflate the Arab IQ to make it seem like the Black IQs were lower. If he had been more honest and used a more adjacent population like Pakistanis his estimate would have been lower as Pakistanis in the UK score lower than Indians and Blacks.

figure 8

If he had used IQ estimates for Arabs like a sane person his finding would be inverted as it would probably even lower the offspring IQ. In no study has any Arab nation been assigned a higher IQ than American Blacks. Even the wealthiest Arab nations perform worse than Blacks on aptitude tests like PISA as I show below. Qatar with its massive Expat population perform far worse than Black Americans. The UAE only outperforms them by 1 point. Nations like Algeria  and Tunisia (where the Arab soldiers were from) are at the bottom.

figure 9

Remember that Althype is where race realists get a lot of their data. His articles are full of this sort of nonsense. I'd recommend getting acquainted with his articles in order to better understand hereditarian delusions. His name will pop up many times in this blog series because of this. These sort of errors and blatant faulty logic aren't one offs. This is what happens when you allow midwits to do your propaganda. I'd like to acknowledge Steve Sailer for the table above!

2. Ishihara (1969)

This is a basically a Japanese version of Eyferth's study with basically the same result. Just like Germany, After Japan's defeat in WW2, America garrisoned (and still does) troops on the Japanese mainland. As we would expect, soldiers had illegitimate children with the local women. The study above was conducted by Japanese scientists to find whether there were intelligence differences between the offspring of white and black GIs.

Just like in Eyferth's study, there are no IQ differences between the Hapas whether White or Black. It should be noted that both races scored lower than the average of fully Japanese kids because these children were in foster care and thus in a far worse environment than the average Japanese child with 2 parents.

General Findings with Adoption Studies

 Adoption studies have been shown to significantly raise IQ and are in general contradiction of the hereditarian hypothesis. This meta-analysis of over 60 adoption studies including nearly 18,000 adopted children showed adoption studies to raise IQ by an average of 18 IQ points (1.2 SD).  Adoption studies are generally the best method for finding the influence of genes of intelligence, compared to something like early intervention. Early intervention does lead to increases in IQ but the effects fade away into adulthood as the children leave the enriched environments and go back to poor environments. Adoption studies don't have this problem. 

Terminology:

"Hapa" - Someone with half East-Asian ancestry

"Mullato" - Someone with 1 black and 1 white parent

I deliberately use these terms to avoid ambiguity to the nature of the childrens' admixture.

 In part 2, I will talk about the East Asian adoption studies.

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