Nature’s egg and seed plan unz.com/jthompson/natu…
Investigators into the genetics of intelligence are given a rough ride in contemporary academia, where genetics generates a hostility not meted out to sociological explanations.
No engineering analogy will fit the intricacies of biology, but the implication is clear: DNA is what makes stuff happen, given only some basic environmental circumstances habitually found on this planet. The genetic code is causal.
Research is a life-consuming business. Some researchers give up their weekends, most don’t. Twins Early Development Study has more than 12,000 twins, and has generated 55 million items of data, described in over 300 published papers and 30 PhDs. Respect.
“Inherited DNA differences are by far the most important systematic force in making us who we are”.
Whole programs have been devoted to giving books to families, because number of books in the house predicts children’s scholastic achievements. On the contrary, Plomin simply shows, “parents who like to read have children who like to read”.
Identical twins are more concordant for divorce (55%) than fraternal twins (16%). Divorce does not rain down unbidden from the sky: it happens more frequently to those who are joyful, engaged with life, emotional and impulsive. So there.
3 genetic clusters of psychiatric disorders:
A) Internalizing disorders like anxiety and depression;
B) externalizing disorders like antisocial behaviour, alcohol & drugs;
C) Psychotic disorders like schizophrenia, bipolar disorder & major depression.
Genetic underpinnings matter
A) Internalizing disorders like anxiety and depression;
B) externalizing disorders like antisocial behaviour, alcohol & drugs;
C) Psychotic disorders like schizophrenia, bipolar disorder & major depression.
Genetic underpinnings matter
Vocabulary, spatial ability & abstract reasoning yield genetic correlations greater than 0.5. Some genetic effects are specific to each cognitive ability, but most genetic effects are general to all cognitive abilities. “g” has a biological reality.
Genetic influence is caused by many genes of small effect. These effects affect many traits. Likely that generalist genes result in generalist brains. The multi-purpose brain let humans survive ancient threats, by using tried and tested general problem-solving abilities.
Children in the same family with the same parents are different because siblings correlate only .4 for intelligence, an average 13 IQ point of difference, compared to 17 IQ points for pairs chosen at random in the general population.
Does life really have turning points, or are they only unfoldings?
Thinking of human beings as no more than flotsam battered by waves of historical inevitability is as demeaning as viewing them as only constructions propped up by genes.
Thinking of human beings as no more than flotsam battered by waves of historical inevitability is as demeaning as viewing them as only constructions propped up by genes.
In all these confections the essential features of being human seem lost, subsumed into vexatious particulars, and stripped of agency and dignity. We are torn between our predicaments and our proclivities.
Heritability of outcomes is an index of equality of opportunity: if environments were all-powerful & varied unfairly that would set heritability to zero. The high heritability of school achievement of 60% in the UK suggests that the system is uniformly OK.
UK kids at selective secondary schools do a whole grade better than unselective state schools at 16 years, fee-paying parents note. When Plomin controlled for the factors used to select students the difference shrinks to 1%, consistent with selection being meritocratic
University students would have been just as likely to be accepted by the best universities if they had not gone to a selective school, which are seen as conferring an unfair advantage. Wiser to apply from an unselective State school. Private education is not worth the money.
Dumb molecules, the same in each of our trillions of cells, produce life in all its amazing complexity. A rope ladder held together by 3 billion weak rungs, twisted into a double helix so that it forms a spiral, consisting of a 4 letter alphabet which creates 64 DNA words.
This is an explosive book. Environmentalist position looking threadbare. DNA story capturing new ground of self-created environmental niches, environmentalism in retreat, reduced to saying that really bad environments would change the picture.
This is also a sobering book. It changes our views of ourselves and, shorn of any reassuring nostrums, invites us to understand our limitations, and to work within them. Genetics deals us a hand to play, and we must play it as best we can.
