posted 22 January 2004


William H. Calvin, "The evolution of structured thought." Talk for UW Psychiatry Grand Rounds (22 January 2004). See also

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An earlier version of this talk was given at
Victoria University of Wellington, New Zealand on 7 January 2004.

William H. Calvin 
it's an image, you need to type it, not copy it (spam...)       
 University of Washington


Abstract  Our brain may have a common way of handling structured stuff, one of the reasons why that some functions might come (and go, in strokes or senility) as a package deal.  The ability to order our thoughts (“I think I saw him leave to go home” is three sentences nested inside a fourth, like Russian dolls) was probably a package deal.  This structured thought package likely brought us not only syntax and contingent planning but also games with rules, gambling, chains of logic, our fascination with discovering hidden patterns in the world around us, and even our ability to appreciate structured music.

In evolutionary time, package deals most commonly arise via multiple function structures (a concrete example is the curb cut, paid for by wheelchair considerations but used 99% of the time for “free” uses).  Like the use of curb cuts by skateboarders, most of our secondary uses of structured thought circuitry are still full of bugs, just out of beta.  Take logic:  as merchants know all too well, our decision making is easily swayed by the last thing we happen to hear, which often overrides our more rational consideration of the alternatives.  Trying to impose order on chaos, we find patterns where none exist, sometimes imagining voices when it is only the sounds of the wind.  Like Windows, we still hang up (or even crash from seizures).  Lacking a reset button, we seek mind-clearing retreats into a here-and-now mental state when the future prospects start to loop endlessly.

There is a tendency to view evolution as producing well-tested, efficient processes and structures.  For higher intellectual functions, we might best view them as potentially highly inefficient and buggy, capable of great mischief and mistakes as their technologically-assisted power increases.

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A Brief History
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A Brain for All Seasons

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