IQ Largely Determined by Genes: The Evidence Builds
Some of the determinants of IQ in the brain include 1. The efficiency of the connections in the brain, 2. The quality of the myelin sheaths around axons in the brain, 3. The volume and location of gray matter tissue in the cerebral cortex, 4. The volume of sub-cortical gray matter, 5. The speediness of white matter tracts and more.
All of these variables are highly heritable. As a person ages, the influence of his genetic makeup on his IQ will increase.
The heritability of general cognitive ability increases significantly and linearly from 41% in childhood (9 years) to 55% in adolescence (12 years) and to 66% in young adulthood (17 years) in a sample of 11 000 pairs of twins from four countries, a larger sample than all previous studies combined. _MolecularPsychiatry
A lot of research that is intended to debunk the link between IQ and genes, is conducted prior to the most significant genetically programmed changes in the brain -- in adolescence. The connections between genes and IQ apparently do not fully kick in until early adulthood.
A rich environment can raise a young child's tested IQ during early childhood, but if the genes do not support an elevated cognition, the artificially high IQ scores will not be maintained into adulthood. Such faulty research designs tend to distort comparisons of mean IQ scores between different population groups.
Here at the Al Fin Institutes of Next Level Research, we expect any significant IQ differences between races, genders, and ethnicities to be eliminated by advanced neuroscience within the next few decades. But the currently fashionable denial of the link between genes and IQ is immensely destructive -- particularly to low IQ population groups. The only way to achieve the neuroscientific uplifting of all humans' intelligence, is by an honest pursuit of the realities involved. That uplifting is what is being postponed by the fanatical adherence to political correctness which is endemic to western politics, academia, media, and popular culture.
The modern-day dieoff leftism that dominates western cultures is a deadly and lethal meme that requires attention, before it accomplishes the human dieoff it fervently seeks.