Tuesday, 25 November 2014

How are highly intelligent people sometimes born to unintelligent parents (and ancestors)?

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This (assuming the phenomenon is real) seems hard to explain in the way that intelligence is normally considered - in terms of intelligence being a consequence of very large numbers (thousands?) of genes-for-intelligence. With intelligence genes conceptualized as additive in effect, and in such large numbers, it is hard to understand how a very highly intelligent child could emerge by chance from low intelligence parents.

But if  person's level of intelligence is also determined by the number of deleterious mutations they inherit from their parents, and these mutations are numbered in tens - then it is imaginable that, by chance, a child may be born with very few deleterious mutations, despite his parents having a relatively heavy mutation load.

This notion is perhaps testable, on the basis that a low mutation load should be associated with generally higher fitness - so the high intelligence child of low intelligence parents would be expected to be (on average) taller, healthier, more symmetrical, more long-lived than his low intelligence parents.

2 comments:

Peter G Brown said...

By the way, OT but have you seen this http://www.gizmag.com/synesthesia-training-iq-boost/34849/.

Very little fuss made over it. It seems like this is either rubbish or the most important research of the 20th century so far (12pt IQ gain!!). I've read the attached paper and confess to not understanding it enough to judge it properly except to say it is a small sample size.

Bruce Charlton said...

Various things can boost IQ test scores, but that is not the same as increasing actual general intelligence. I don't believe that real intelligence can be increased.