Intelligence; nature v nurture (again). Prof. Robert Plomin.

[Gruach]

Listening to The Life Scientific on R4 right now.

Professor Robert Plomin talks to Jim Al-Khalili about what makes some people smarter than others and why he's fed up with the genetics of intelligence being ignored. Born and raised in Chicago, Robert sat countless intelligence tests at his inner city Catholic school. College was an attractive option mainly because it seemed to pay well. Now he's one of the most cited psychologists in the world. He specialized in behavioural genetics in the mid seventies when the focus in mainstream psychology was very much on our nurture rather than our nature, and genetics was virtually taboo. But he persisted, conducting several large adoption studies and later twin studies. In 1995 he launched the biggest longitudinal twin study in the UK, the TED study of ten thousand pairs of twins which continues to this day. In this study and in his other work, he's shown consistently that genetic influences on intelligence are highly significant, much more so than what school you go to, your teachers or home environment. If only the genetic differences between children were fully acknowledged, he believes education could be transformed and parents might stop giving themselves such a hard time.

Oh fabulous - he's ducked the "racial inheritance" question.

That's me told then! Sorry, have not "met" Shegot. Definitely fraternal!

I'm adopted. I believe totally in nature and very little in nurture.

I was talented in a particular area from a very early age. I went on to study this at degree level. No one in my adopted family had any of these skills.

When I met my birth mother, her mother had this particular skill, and was renowned for it in the city she lived in. My birth father also had a similar talent. None of my adopted family could do any of it....

A couple of fun papers:

The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence:
www.pnas.org/content/111/42/15273.full

"...we show that other broad domains of behavior such as personality and psychopathology also account for genetic influence on GCSE scores beyond that predicted by intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE scores."

Meta-analysis of the heritability of human traits based on fifty years of twin studies:
www.gwern.net/docs/2015-polderman.pdf

"We have conducted a meta-analysis of virtually all twin studies published in the past 50 years, on a wide range of traits and reporting on more than 14 million twin pairs across 39 different countries. Our results provide compelling evidence that all human traits are heritable: not one trait had a weighted heritability estimate of zero."

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@ cressetmama: Energy and determination counts for a vast amount, and some of it is probably inherited, but where on the genome is the chromosome to be found?

DD was definitely born with self-motivation, determination and a quite generous dash of intelligence. She has several personality variants (at home, in class, with friends... ) but there's a core to them all that has always been there. As parents I suppose we could have caused som damage, but we certainly didn't do anything much to encourage her qualities. You should NOT buy PiqueABoo's Perfect Parenting book.

It looks like many of these traits are polygenic, dependent on combinations of lots of genes. They're working on it and the hunt keeps getting cheaper courtesy of cheaper computing power. Some people in the field have suggested they might pin down intelligence within a decade or so.

@Soveryupset: I truly believe that had they had more opportunities growing up...

Yes e.g. DD is a quite decent little pianist and that required exposure to a piano. I think a key part of parenting is essentially making opportunities to discover their "appetites and aptitudes" (one of the Plomin gang's catch-phrases).

I also found this really interesting when it was on yesterday morning.

He said that whether a child goes to the worst school or the best school, it makes a maximum difference of about 20%, with two thirds of the influence being genetic.

Genes are certainly an important factor in intelligence; however, environment must make a big difference as well----look at the Flynn phenomenon.

I was fascinated by the Flynn effect during the writing of an essay on teaching the digital nature but the societal increase in intelligence that he attributes to complex and immersive mass media isn't completely proven, or is it now? He was rather obscure at the time I took an interest and then life moved on.

At least superficially, it ties in with the exposure to experience and opportunities; I'm no expert nor in research but Flynn seems to think that knowing something exists just from seeing it on TV is sufficient to count as experience and exposure, hence the huge jump in intelligence through the 20th and 21st centuries.

Teaching the digital native.... sorry!

the Flynn effect

20% is not insignificant though....