Ron Unz and IQ

I seem to be a consistent critic of Ron Unz, editor of "The American Conservative". I noted yesterday (and earlier) that his idea of low criminality among Hispanics is contradicted by Obama's deportation  statistics and I also took a few potshots at his theory that IQ differences between nations are mostly the effect of environmental  factors. 

So I am pleased that Richard Lynn has now given a systematic reply to Unz on the IQ question.  Lynn echoes some of the points I made (and I did get an email from Lynn saying he liked my article) but his reply is far more detailed and scholarly and, I think, a good reply  to Unz's claims.

Unz has replied to Lynn and it looks to me that the two sides are converging, with the differences being in matters of degree. Both parties agree that the environment has some influence but Lynn makes a strong case for the importance  of genetics.

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Could a brain scan tell you how smart you are? Research shows intelligence linked to strength of neural connections

More evidence that IQ is genetically determined.  We are now getting an idea of  the specific mechanisms involved

Research suggests that 10 per cent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left lateral prefrontal cortex to the rest of the brain.

The findings, published in the Journal of Neuroscience, establish 'global brain connectivity' as a new approach for understanding how human intelligence relates to physiology.

'Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is,' said Michael Cole, PhD, a postdoctoral research fellow in cognitive neuroscience at Washington University and lead author of the study.

He says the research is the first to provide compelling evidence that neural connections between the lateral prefrontal cortex and the rest of the brain make a unique and powerful contribution to the cognitive processing underlying human intelligence.

'This study suggests that part of what it means to be intelligent is having a lateral prefrontal cortex that does its job well; and part of what that means is that it can effectively communicate with the rest of the brain,' added study co-author Todd Braver, PhD, professor of psychology in Arts & Sciences and of neuroscience and radiology in the School of Medicine.

One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a 'flexible hub' that uses its connectivity to monitor and influence other brain regions.

'There is evidence that the lateral prefrontal cortex is the brain region that "remembers" the goals and instructions that help you keep doing what is needed when you're working on a task,' said Prof Cole.  'So it makes sense that having this region communicating effectively with other regions (the "perceivers" and "doers" of the brain) would help you to accomplish tasks intelligently.'

While other regions of the brain make their own special contribution to cognitive processing, it is the lateral prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand. This happens in much the same way that the conductor of a symphony monitors and tweaks the real-time performance of an orchestra.

The findings are based on an analysis of functional magnetic resonance (fMRI) brain images captured as study participants rested passively and also when they were engaged in a series of mentally challenging tasks associated with fluid intelligence, such as indicating whether a currently displayed image was the same as one displayed three images ago.

Previous findings relating lateral prefrontal cortex activity to challenging task performance were supported. Connectivity was then assessed while participants rested, and their performance on additional tests of fluid intelligence and cognitive control collected outside the brain scanner was associated with the estimated connectivity.

Results indicate that levels of global brain connectivity with a part of the left lateral prefrontal cortex serve as a strong predictor of both fluid intelligence and cognitive control abilities.

More  HERE