Intelligence

This commentary and its aim grew fast, and here is why.

I read this paper a few days after its publication. The very precise choice of words, the exceptional expertise of authors and the usefulness for people, from physicians to scientists and students, stroke me. So I decided to make my homework like a student in a master on genetics.

"Life is an intelligence test. During the school years, differences in intelligence are largely the reason why some children master the curriculum more readily than other children. Differences in school performance predominantly inform prospects for further education, which in turn lead to social and economic opportunities such as those related to occupation and income. In the world of work, intelligence matters beyond educational attainment because it involves the ability to adapt to novel challenges and tasks that describe the different levels of complexity of occupations. Intelligence also spills over into many aspects of everyday life, such as the selection of romantic partners and choices about health care. This is why intelligence — often called general cognitive ability — predicts educational outcomes, occupational outcomes and health outcomes better than any other trait. It is also the most stable psychological trait, with a Pearson correlation coefficient of 0.54 from 11 to 90 years of age. "
Plomin and von Stumm

Life is indeed an intelligence test.

Everyone did this experience. From playing with toys at home, from finding a Rubik cube solution and solving maths problems later we tested our intelligence. All of this begins with an inescapable question: is my brain able to solve this problem? And this story began hundred of thousands of years ago when we went away the Zambian area and migrate to the northeast and to the south-west... Every new environment needed to solve problems in order to survive and thrive.

"During the past century, genetic research on intelligence was in the eye of the storm of the nature– nurture debate in the social sciences. In the 1970s and 1980s, intelligence research and its advocates were vilified. The controversy was helpful in that it raised the quality and quantity threshold for the acceptance of genetic research on intelligence. As a result, bigger and better family studies, twin studies and adoption studies have amassed a mountain of evidence that consistently showed substantial genetic influence on individual differences in intelligence. Meta-analyses of this evidence indicate that inherited differences in DNA sequence account for about half of the variance in measures of intelligence"

What is this storm on the nature-nurture debate about? It is the denial of intelligence heritability, the denial of any genetic influence on cognitive abilities: the tabula rasa's myth.

Very early in the 20th-century studies on intelligence were vilified. The great politically correct "excuse" was WWII and the so-called nazi eugenism. Every scientific research to find biological roots to human traits was stigmatised as a resurgence of nazism. The mechanistic rhetoric was that if biological inter-ethnic differences and inter-individuals differences (which is obvious according to observation) were found, this could be another time used by totalitarian regimes. Nazis were not eugenists, they were mass murderers. They didn't know anything about genomics or intelligence, they didn't care about science they were warriors of the evil. They followed the Sion's protocols and they criminally used very primary and approximative phenotypes characterisations to try to eliminate handicapped people and Jews. This historical fact which is related to one of the most brutal regime of the modern era was and is not anything else than a big excuse for the left. Indeed its agenda, previous the WWII, was already the Marxist theory and the preeminence of nurture. Communists in USSR did genetic experiments. It is paradoxical that Lysenko's flawed experiments are so badly known and reported by those who justified their stances against genetics by the nazis regime. This debate is legitimate from a scientific perspective but it is sterile from an ideological one. Fortunately, thanks to the great research of Jensen, Rushton, Lynn and Flynn during the second half of the 20th century, the debate was enlightened by facts.