I still follow stuff about small world networks and power laws… and look, here they pop up again. Your neurons have 13 degrees of separation!

That isn’t really what the article is about, of course; it’s more about the way in which this sort of organizational structure allows the brain to live at the very edge of chaos, tipping between stability and chaos as we think — and that in fact, the chaos maybe what drives the classic definition of intelligence.

The balance between phase-locking and instability within the brain has also been linked to intelligence – at least, to IQ. Last year, Robert Thatcher from the University of South Florida in Tampa made EEG measurements of 17 children, aged between 5 and 17 years, who also performed an IQ test.

He found that the length of time the children’s brains spent in both the stable phase-locked states and the unstable phase-shifting states correlated with their IQ scores. For example, phase shifts typically last 55 milliseconds, but an additional 1 millisecond seemed to add as many as 20 points to the child’s IQ. A shorter time in the stable phase-locked state also corresponded with greater intelligence – with a difference of 1 millisecond adding 4.6 IQ points to a child’s score.

— Disorderly genius: How chaos drives the brain – life – 29 June 2009 – New Scientist.

Now, of course we know this isn’t the only sort of intelligence. Nonetheless, it’s a fascinating result, and the article also ties it to research on autism and schizophrenia.