Accidental Evidence of HH: Regression to the mean in MR rates

My current obsession with the mentally retarded has led me to some further evidence for the  herditarian hypothesis of the black-white IQ difference to add to Chuck's magnum opus.  Drews et. al. (1995) conducted a thorough case-control study of retarded children in Atlanta. 

There is some great data in the paper that is well analyzed and presented.  The author's interpretation of the results would have been improved if they recognized that IQ was heritable which simply explains the higher number of MR children born to women with lower educational status.  What is more interesting though is that having a black mother is a risk factor for MR after correcting for educational attainment.  Other factors being equal, a college educated black mother has the same risk of having a retarded child as a white mother with a high school education. 

This is analagous to the famous SAT - Race -  SES  graph and what you would expect to observe if  the B-W IQ difference is heritable.  The probability of a black woman having an MR child would be higher than that of a white women with the same IQ.   Of course there are other explanations.  Chapman (2008) suggest intergenerational risk factors

To fully address this problem, we may need to consider intergenerational risk factors, which involve the mother’s own developmental history. Maternal intergenerational factors clearly play a role in low birthweight ..., and it is likely that other aspects of development, including cognitive development, also have an intergenerational component .

Intergenerational risk factors that affect cognitive development. What could those be?

Evolution did not stop at the neck: PKU

Phenylketonuria is a rare inherited genetic disease (incidence ~ 1/15000) that left untreated leads to retardation and seizures.  It can be treated and and most first world newborns are tested.  With a special diet most suffers are spared a ride on the short bus although a meta analysis (Moyle 2007) showed PKU patients to have average IQs approximately 0.5 of an SD lower than those of controls.  So is the incidence of PKU distributed evenly throughout human sub-populations/races?  Probably not, Hardelid (2007) found the incidence among Europeans about 10 times that of individuals of African descent.

The Age of the Renowned Cryptozoologist

History Channel’s Monsterquest is one of the most thought provoking shows on TV. Each episode begins with a description of a putative monster from and  “experts” in the field, say the swimming Sasquatch of Prince Edward Island.  Then the episodes documents a well financed aunt in the wilderness to find scientifically in convertible evidence of the creature’s existence. Despite the inclusion of drone aircraft, night vision equipment and ground penetrating radar the investigators fail to find the swimming Sasquatch. But does repeatedly failing to find the Sasquatch support its non-existence or do we just need to wait for the falsification of the no Sasquatch hypothesis? What would Karl Popper say?

The show finds pro Sasquatch experts such as Lauren Coleman a “renowned cryptozoologist."   The term “renowned cryptozoologist” is troublesome.  If Coleman was truly renowned he would have to find something and he would become an orthodox zoologist. But today you can get for famous for repeatedly failing to prove the right hypothesis.   The country is full of educrats doggedly trying to establish that the black-white IQ gap is not inherent and can be bridged by innovative pedagogy.  Indeed renowned cryptozoologists are in the highly esteemed company of Geoffrey Canada and Michelle Rhee.  We all await the day when Sasquatch will swim into New York harbor and the KIPP academies will close the gap.

HBD - Race not Required

Many people use HBD as a synonym for race realism when a broader definition is more is more useful. Half Sigma defines HBD as a superset of race realism:

"Human biodiversity is an acknowledgment that humans differ from each other in various ways because of our different genotypes. Differences include, but are not limited to, physical appearance, athletic ability, personality, and cognitive abilities."

To deny HBD is to embrace blank slatism which is easy to refute and more importantly puts the deniers on the moral low ground.  Like opponents of stem cell research HBD deniers prevent the sufferers  genetic diseases possible cures.  

Take fragile X, a hereditary genetic condition that presents its sufferers with a one way ticket to retard town.  Should we deny HBD in a blank slate fog or should we join Doris Buffett and try to save the children from a lifetime of free bus passes and dish washing jobs.  HBD is for the children!