40% of IQ Differences Among Preschoolers Stems from Genetic Differences

[Hersir]

40 percent of IQ differences among preschoolers stems from genetic differences but that heritability rises to 60 percent by adolescence and to 80 percent by late adulthood

Decades of genetics research have shown...that people are born with different hereditary potentials for intelligence and that these genetic endowments are responsible for much of the variation in mental ability among individuals. Last spring an international team of scientists headed by Robert Plomin of the Institute of Psychiatry in London announced the discovery of the first gene linked to intelligence. Of course, genes have their effects only in interaction with environments, partly by enhancing an individual's exposure or sensitivity to formative experiences. Differences in general intelligence, whether measured as IQ or, more accurately, as g are both genetic and environmental in origin--just as are all other psychological traits and attitudes studied so far, including personality, vocational interests and societal attitudes. This is old news among the experts. The experts have, however, been startled by more recent discoveries.

Continues http://alfin2100.blogspot.com/2012/0...-world-so.html

[Ælfrun]

It appears that the effects of environment on intelligence fade rather than grow with time. In hindsight, perhaps this should have come as no surprise

What is that saying?

As we get older, we become wiser

of corse it does because we learn through our negative and positive experiences. We constantly learn every day, so obviously our IQ will be higher as we age.

Many people still mistakenly believe that social, psychological and economic differences among families create lasting and marked differences in IQ.

This is most certainly untrue because people mostly learn how to adapt to their surroundings no matter what the situation is. Children often heal from trauma in childhood. If IQ is mostly genetic, I hope this does not mean I will turn into my mother

[VedicViking]

It appears that the effects of environment on intelligence fade rather than grow with time. In hindsight, perhaps this should have come as no surprise

What is that saying?

It’s due to something called gene amplification. The effects of some genes get stronger as we age. This is why the IQs of identical twins get more and more similar over time. It’s also presumably why there’s more of a difference in cognitive ability between an adult human and an adult chimp, than between a baby human and a baby chimp.

[Horagalles]

Intelligence is certainly genetic to the core. And the gap in difference shows that the genetic differences in this field have actually be weighted stronger then the rest of genetic information.

...
This is most certainly untrue because people mostly learn how to adapt to their surroundings no matter what the situation is. Children often heal from trauma in childhood. If IQ is mostly genetic, I hope this does not mean I will turn into my mother

Genetically you got just 50% from your mother. And then mendels laws may also play a role.

[Naglfari]

There is an earlier discovery of the gentic link in 2006.

http://www.ncbi.nlm.nih.gov/sites/en...&term=16801949

The synaptosomal-associated protein of 25 kDa (SNAP-25) gene plays an integral role in synaptic transmission, and is differentially expressed in the mammalian brain in the neocortex, hippocampus, anterior thalamic nuclei, substantia nigra and cerebellar granular cells. Recent studies have suggested a possible involvement of SNAP-25 in learning and memory, both of which are key components of human intelligence. In addition, the SNAP-25 gene lies in a linkage area implicated previously in human intelligence. In two independent family-based Dutch samples of 391 (mean age 12.4 years) and 276 (mean age 37.3 years) subjects, respectively, we genotyped 12 single-nucleotide polymorphisms (SNPs) in the SNAP-25 gene on 20p12-20p11.2. From all individuals, standardized intelligence measures were available. Using a family-based association test, a strong association was found between three SNPs in the SNAP-25 gene and intelligence, two of which showed association in both independent samples. The strongest, replicated association was found between SNP rs363050 and performance IQ (PIQ), where the A allele was associated with an increase of 2.84 PIQ points (P=0.0002). Variance in this SNP accounts for 3.4% of the phenotypic variance in PIQ.

Me: