William H. Calvin

Brief essays and book excerpts covering biology and psychology, the brain and earth sciences, anthropology and evolution.


  The eight-hour PBS television series, Evolution, for which I was a science advisor, will soon be seen in reruns:  Tuesday, May 14: Darwin's Dangerous Idea.  Tuesday, May 21: Great Transformations and Extinction! Tuesday, May 28: The Evolutionary Arms Race and Why Sex? Tuesday, June 4: The Mind's Big Bang and What About God?, 9-11pm.


From an interview in Psychology Today:

ELIZABETH LOFTUS: A flimsy curtain separates memory from imagination. Suggestions, strong and subtle, can make people believe that they had experiences in childhood that they almost certainly did not have.

WILLIAM CALVIN: Yes, we've long known how false memories can be created. Human memory is always having to contend with the power of suggestion. After all, most happenings aren't "good stories" that fit our narrative expectations, so with retelling they get "improved."

EL. But who is most susceptible to "adopting" a memory? And who is most resistant? There ought to be a lot of individual variability in the susceptibility to false memories. Maybe it correlates with genetics, intelligence and other individual differences. Perhaps we'll develop recipes for what works with various personality types.

WC: Who am I, if not my memories -- and if they're not mine, what does that say about me? It must be threatening to a lot of people, to think that their memories aren't their own.

EL: Memory is creative. There, I've said it all.

WC: But human memory isn't supposed to be creative. Facts are facts, and the past is finished. So when memory scrambles things, you get annoyed.....

Previous issues of
Science Surf




this issue is 2001.1



Elizabeth F. Loftus is Professor of Psychology and Adjunct Professor of Law, University of Washington, Seattle WA 98195-1525 USA, http://faculty.washington.edu/eloftus.

William H. Calvin is Affiliate Professor of Psychiatry and Behavioral Sciences, University of Washington, Seattle WA 98195-1800 USA, http://faculty.washington.edu/wcalvin.  


See the rest of the Psychology Today interview.

By the same authors:  "The Poet as Brain Mechanic:  A 2050 Version of Physics for Poets," a futurist piece in the style of a 2050 course description.


EL: So what's the next decade of memory therapy going to be like? Psychotherapy with a pharmaceutical booster? I can envision 21st-century memory doctors helping clients with their academic performance by prescribing additives for the coffee they drink before an upcoming test. They might even begin their psychotherapy sessions with a drug that enhances the malleability of memory, making the patient more susceptible to positive suggestions that occur later in their session.

WC: More of human memory will move offline. We'll rely more on digital storehouses full of video and audio files of our lives. It'll happen because digital storage is cheap -- and hopefully because we also realize how unreliable human memory can be. Maybe some of the storehouses will be portable, like today's music for joggers, and will provide you with help in remembering people and places.

EL: But when we do get the false memory recipes down pat, we'll be left with critical questions. Who controls that technology? What brakes should be imposed on police, lawyers, advertisers and others who try to manipulate people using these findings? When memory creation technology becomes readily available, how will society protect itself from misuse? We'll need to constantly keep in mind that memory, like liberty, is a fragile thing.

My answer to the Edge query:  

Where did the moon go?  When, every few years, you see a bite taken out of the sun or moon, you ought to remember just how frightening that question used to be.  It became clockwork when the right viewpoint was eventually discovered by science (imagining yourself high above the north pole, looking at the shadows cast by the earth and the moon).
     But there was an intermediate stage of empirical knowledge, when the shaman discovered that the sixth full moon after a prior eclipse had a two-third's chance of being associated with another eclipse. And so when the shaman told people to pray hard the night before, he was soon seen as being on speaking terms with whomever ran the heavens.
     This helped convert a part-time shaman into a full-time priest, supported by the community.  This can be seen as the entry-level job for philosophers and scientists, who prize the discoveries they can pass on to the next generation, allowing us to see farther, always opening up new questions while retiring old ones.  It's like climbing a mountain that keeps providing an even better viewpoint.

How the Shaman Stole the Moon

How the Shaman
 Stole the Moon
(Bantam 1991; Authors Guild reprint 2001) is my archaeoastronomy book, a dozen ways of predicting eclipses — those Paleolithic strategies for winning fame and fortune by convincing people that you're (ahem) on speaking terms with whoever runs the heavens.
SUPPLEMENT: "Leapfrogging Gnomons" describes how to survey a 700-km north-south line without modern instruments.



One of my favorite books is by 
Edward O. Wilson

Unity of Knowledge

(Knopf 1998). 

     Wilson argues for consilience -- that everything in our world is organized by a small number of fundamental natural laws that comprise the principles governing every branch of learning.
     There is a long excerpt in both the March and April 1998 issues of
The Atlantic Monthly.
...let us begin by simply walking away from Foucault, and existentialist despair. Consider this rule of thumb: to the extent that philosophical positions both confuse us and close doors to further inquiry, they are likely to be wrong....
     Most of the issues that vex humanity daily -- ethnic conflict, arms escalation, overpopulation, abortion, environmental destruction, and endemic poverty, to cite several of the most persistent -- can be solved only by integrating knowledge from the natural sciences with that from the social sciences and the humanities. Only fluency across the boundaries will provide a clear view of the world as it really is, not as it appears through the lens of ideology and religious dogma, or as a myopic response solely to immediate need. Yet the vast majority of our political leaders are trained primarily or exclusively in the social sciences and the humanities, and have little or no knowledge of the natural sciences. The same is true of public intellectuals, columnists, media interrogators, and think-tank gurus. The best of their analyses are careful and responsible, and sometimes correct, but the substantive base of their wisdom is fragmented and lopsided.

-- Edward O. Wilson,
                 Consilience: Unity of Knowledge

Last year, Edward O. Wilson was the first recipient of the $100,000 Kistler Prize from the Foundation for the Future.  This year, the second recipient is Richard Dawkins.  Here are some excerpts from the writings of Richard Dawkins.

Richard Dawkins, Climbing Mount Improbable (Norton, 1996).

"Darwinism is not a theory of random chance. It is a theory of random mutation plus non-random cumulative natural selection. Why, I wonder, is it so hard for even sophisticated scientists to grasp this simple point?" [p.75]
        "Evolution is an enchanted loom of shuttling DNA codes, whose evanescent patterns, as they dance their partners through geological deep time, weave a massive database of ancestral wisdom, a digitally coded description of ancestral worlds and what it took to survive in them." [p.326]


Richard Dawkins, The Extended Phenotype: The Long Reach of the Gene (Oxford UP, 1982).

        "Any suggestion that the child's mathematical ineptitude might have a genetic origin is likely to be greeted with something approaching despair: if it is in the genes "it is written", it is "determined" and nothing can be done about it; you might as well give up attempting to teach the child mathematics. This is pernicious rubbish on an almost astrological scale. Genetic causes and environmental causes are in principle no different from each other. Some influences of both types may be hard to reverse, others may be easy."

An Open Letter to Prince Charles (published in The Observer)
by Richard Dawkins

Sunday May 21, 2000

Your Royal Highness,

Your Reith lecture saddened me. I have deep sympathy for your aims, and admiration for your sincerity.  But your hostility to science will not serve those aims; and your embracing of an ill-assorted jumble of mutually contradictory alternatives will lose you the respect that I think you deserve.  I forget who it was who remarked:  "Of course we must be open-minded, but not so open-minded that our brains drop out....

     On the other hand, we must beware of a very common misunderstanding of Darwinism.  Tennyson was writing before Darwin but he got it right.  Nature really is red in tooth and claw.  Much as we might like to believe otherwise, natural selection, working within each species, does not favour long-term stewardship.  It favours short-term gain.  Loggers, whalers, and other profiteers who squander the future for present greed, are only doing what all wild creatures have done for three billion years.
     No wonder T. H. Huxley, Darwin's bulldog, founded his ethics on a repudiation of Darwinism.  Not a repudiation of Darwinism as science, of course, for you cannot repudiate truth.  But the very fact that Darwinism is true makes it even more important for us to fight against the naturally selfish and exploitative tendencies of nature.  We can do it.  Probably no other species of animal or plant can.  We can do it because our brains (admittedly given to us by natural selection for reasons of short-term Darwinian gain) are big enough to see into the future and plot long-term consequences.  Natural selection is like a robot that can only climb uphill, even if this leaves it stuck on top of a measly hillock.  There is no mechanism for going downhill, for crossing the valley to the lower slopes of the high mountain on the other side.  There is no natural foresight, no mechanism for warning that present selfish gains are leading to species extinction - and indeed, 99 per cent of all species that have ever lived are extinct.
     The human brain, probably uniquely in the whole of evolutionary history, can see across the valley and can plot a course away from extinction and towards distant uplands.  Long-term planning - and hence the very possibility of stewardship - is something utterly new on the planet, even alien.  It exists only in human brains.  The future is a new invention in evolution.  It is precious.  And fragile.  We must use all our scientific artifice to protect it.
     It may sound paradoxical, but if we want to sustain the planet into the future, the first thing we must do is stop taking advice from nature.  Nature is a short-term Darwinian profiteer.  Darwin himself said it: "What a book a devil's chaplain might write on the clumsy, wasteful, blundering, low, and horridly cruel works of nature."

More at Edge.

Of course that's bleak, but there's no law saying the truth has to be cheerful; no point shooting the messenger - science - and no sense in preferring an alternative world view just because it feels more comfortable.  In any case, science isn't all bleak.  Nor, by the way, is science an arrogant know-all.  Any scientist worthy of the name will warm to your quotation from Socrates: "Wisdom is knowing that you don't know."  What else drives us to find out?
     What saddens me most, Sir, is how much you will be missing if you turn your back on science.  I have tried to write about the poetic wonder of science myself, but may I take the liberty of presenting you with a book by another author?  It is The Demon-Haunted World by the lamented Carl Sagan.  I'd call your attention especially to the subtitle: Science as a Candle in the Dark .

RICHARD DAWKINS is an evolutionary biologist and the Charles Simonyi Professor for the Understanding of Science at Oxford University; Fellow of New College; author of The Selfish Gene, The Extended Phenotype, The Blind Watchmaker, River out of Eden) (ScienceMasters Series), Climbing Mount Improbable, and Unweaving the Rainbow.

Antonio R. Damasio,
The Feeling of What Happens:
Body and Emotion in the Making of Consciousness

Introducing Antonio Damasio:

The C word has been much in evidence in the last decade, with several new journals and many new books devoted to consciousness.  But in most of the century since William James wrote about consciousness, not too much more was said on the subject because of behaviorism’s emphasis on avoiding what you couldn’t study in the overt behavior of rats and pigeons. 
If you were curious, however, and went and asked the experts, you got answers about consciousness that really led nowhere beyond their local applications, they weren’t roads.  Actually, they seemed like roads but they led you down a garden path.  Let me give several examples.   
      Ask a working neuroscientist about consciousness, and we’d start talking about directing attention.  Now attention is indeed one of about a dozen connotations of the C word that you’ll find in an English dictionary, but there surely isn’t just one unitary mechanism behind all of them – be careful about the reification fallacy, making a thing out of a word – and indeed these dozen connotations would be sorted into somewhat different words in a French or German dictionary.   

     But however useful and appropriate the emphasis on attention, it nonetheless led us down the following garden path.  Surely dogs are conscious, people said, and even a bacterium will “pay attention” if you poke it, and so some people could imagine all living things having irritability would have some form of consciousness.  And if this dilution of the C concept wasn’t bad enough, just try striking two rocks together and watch the sparks fly.  See, they too are irritable!  Even rocks have consciousness!  So much for that garden path.  
So we turn to the other experts, the neurologists and neurosurgeons who deal with unconscious patients all the time.  They don’t necessarily talk about consciousness; they talk about arousibility and alertness and being oriented to time and place, except switching to use the C word when responding to a relative’s question.  Their practical concern is with whether a brainstem injury is getting better or worse, and sleep and wakefulness are dramatically influenced by brainstem projections to cerebral cortex.  So some people say that the brainstem is the “seat of consciousness.”  And others, like Walter Freeman, quip that this is confusing the light switch with the light.  Like attention, important in and of itself, the brainstem is but another garden path for anyone wanting bigger answers about consciousness.  


     I’m reminded of the famous quip of Francis Crick about what science will eventually do with the consciousness concept.  Crick reminds us of fifty years ago, when the big debate seemed to be about the boundary between the living and the nonliving:  Just what properties did it take to be rated “alive”?  Observe, said Crick, that this boundary disappeared into just so much molecular biology.  Nobody much worries about the living-nonliving boundary anymore, just about complicated replication schemes that molecules and cells have.
     Well, Crick quipped, the same thing is going to happen to consciousness, that it will disappear into so much neurobiology.  I don’t take this as a reductionist putdown.  Just as “living” is still a useful word, so the C word will remain useful, but Crick is telling us that we will have a much more nuanced set of notions about what constitutes consciousness and what the mechanisms are.  

     The problem is, how to talk about the varieties of consciousness in such a way as to avoid the beginners’ mistakes like the “little person inside” watching a theater supplied by the sense organs.  Dan Dennett did a nice demolition job in his 1991 book, but we really needed a nice creative job by someone really knowledgeable about the neural substrates.  I had tried my hand at contemplative neural circuitry using Darwinian processes, in my Cerebral Code book, but it was about a working-memory superstructure and I became acutely aware that my proposed mechanism needed a better foundation in the old memories that we amalgamate as feelings and leanings, those six-on-a-scale-of-ten ratings we give our impressions.
     So when the New York Times sent me Damasio’s new book to review, I was immediately taken by it.  It filled the foundational gap that I had inarticulately sensed a few years earlier.  The Feeling of What Happens is a title that really highlights the key point, but even better, it is exactly such a nuanced view of the varieties of things we call consciousness.  This is clearly a must-read book for anyone wanting a neurologist's perspective on one of the ways in which our consciousness exceeds that of the other apes. 

Tony Damasio is the Portuguese-educated professor of neurology at the University of Iowa.  Within the field, he is known as the person who best combines the older techniques of carefully studying stroke and brain-tumor patients for what they can and can’t do, with the newer functional imaging techniques.  But he is more widely known – and to a half-million readers -- as the author of Descartes' Error.  


Books mentioned:

Antonio R. Damasio,
The Feeling of What Happens:
Body and Emotion in the Making of Consciousness

Antonio R. Damasio,
Descartes' Error (1994).



Daniel C. Dennett,
Kinds of Minds (1996).

Daniel C. Dennett,
Consciousness Explained (1991)

William H. Calvin,
The Cerebral Code (1996)

William H. Calvin and Derek Bickerton,
  Lingua ex Machina:
Reconciling Darwin and Chomsky
with the Human Brain
(MIT Press, 2000).



Patrick O'Brian's Aubrey-Maturin Series of 20 novels.  

My appreciation written for WIRED magazine's read.me column:  

"I re-read this extraordinary series of novels because of the depth of portrayal of the major and minor characters, but also because they teach me so much about what science and technology were like two centuries ago.  O'Brian shows you the world-that-was through the eyes of a Tory naval captain (Jack Aubrey), at sea since the age of 12, working his way up to admiral, dealing with the height of 18th-century technology (sailing ships and celestial navigation).  I identify more strongly with his liberally-educated, physician-scientist friend (Stephen Maturin), who went to medical school in Paris during the French Revolution. You see natural history turning into a biological science, bleeding-and-purging medicine starting to learn some physiology -- and, because Maturin is also an intelligence agent for the Admiralty, you see statecraft at work during the Napoleonic Wars.  These books strongly remind you about what scientific ignorance and social conventions can do to your mindset, and how the future will likely judge us as well."




 1. Master and Commander 
 2. Post Captain       
 3. H.M.S. Surprise     
 4. The Mauritus Command   
 5. Desolation Island     
 6. The Fortune of War         
 7. The Surgeon's Mate
 8. The Ionian Mission
 9. Treason's Harbour
10. The Far Side of the World
11. The Reverse of the Medal
12. The Letter of Marque
13. The Thirteen-Gun Salute
14. The Nutmeg of Consolation
15. The Truelove
16. The Wine-Dark Sea      
17. The Commodore   
18. The Yellow Admiral 
19. The Hundred Days 
20. Blue at the Mizzen

The Complete Aubrey/Maturin Series
(20 volumes)


The Feature Article

With each issue of Science Surf, I try to do one longer piece after the shorter ones, often an excerpt from one of my books or essays.  This one is from my new book on paleoanthropology, paleoclimate, and considerations from neurobiology and evolutionary biology:

Human Evolution and Abrupt Climate Change
William H. Calvin

which will be out in Spring 2002 from the University of Chicago Press.  It is already posted full-text on the web and also in Palm download format, for reading on the commute.  It's about what sudden climate flips did to human evolution over the last 2.5 million years.  It includes the climate history and flip mechanisms that I described in The Atlantic Monthly cover story, "The Great Climate Flip-flop" and covers the paleo anthropology as well. 










If I were to give an award for the single best idea anyone has ever had, I'd give it to Darwin, ahead of Newton and Einstein and everyone else.  In a single stroke, the idea of evolution by natural selection unifies the realm of life, mean­ing, and purpose with the realm of space and time, cause and effect, mechanism and physical law.

- Daniel C. Dennett,
Darwin's Dangerous Idea, 1995



I’m starting this little tour at Darwin’s home, sitting at a park bench under a magnificent oak tree that dates back to Darwin’s time here.  Five years after returning from the voyage of the Beagle, Charles Darwin and his young family moved from central London to a pleasant country home about 16 miles to the southeast, near the village of Downe.  He lived here forty years until his death in 1882.  No more voyages around the world, not even trips to the Continent, but Darwin had correspondents everywhere, and sometimes they showed up at his door.

          And it was here at Down House that he raised pigeons, studied earthworms, and dissected barnacles.  Here he sat, pen in hand, and wrote out his books that provided so much of our modern understanding of how nature came to be the way it is.

          But only ten years ago, a scientific pilgrimage to Darwin’s country home was remarkably difficult, unless you got directions from someone who had been here before.  Only the most detailed guidebooks had a mention of Down House, and then only in the fine print.  Get off the train from London at Bromley South or Orpington, and the taxi driver, upon learning your destination, would knowingly suggest that there were much finer country homes to visit than Down House – clearly not understanding that it was Charles Darwin that made Down House so important, not its gardens.

  Arrive, pay off your I-told-you-so taxi driver, and you’d find a low budget operation financed over the decades by the London surgeons, with only several rooms restored to what they were like in Darwin’s day, back before the place had been turned into a girls boarding school in the early 20th century.  There were a few rooms filled with old-fashioned museum cases laden with a dozen coats of paint, but most of the house was in sad need of repairs and unsuitable for visitors.  And this for one of the great scientists of all time, not just one of England’s greats.

          Still, it was enormously inspiring to anyone who understood the intellectual triumph of Charles Darwin, this chance to see where he had thought it all through – his study with his microscope, his chair by the living room fireplace, and his “sand walk” out back, where he went for three walks a day to digest his thoughts.  Often, one supposes, Darwin sloughed through the fine English rain, likely blowing in from the west after forming above the warm Gulf Stream.

          Most people who think a little about evolution are wedded to the basic idea of gradual improvements in efficiency – and not much concerned with the origins of what was later improved (it was just “mutations“).  Yet it was Darwin himself (a point omitted from even the modernized science exhibits at Down House) who first cautioned readers about getting fixated on efficiency, and who – at the same time – offered a route for invention.  He noted that changes in function could be “so important,” that an anatomical structure improved for one function could, in passing, serve some other function that utilized the same anatomical feature.  (Darwin’s example was the fish’s swim bladder serving as a primitive lung.)  Novelties come from those nascent secondary uses, not from a bolt out of the blue, as a cosmic ray mutates a gene.  

If you haven’t seen Down House since the reopening in 1998, there’s a lot more to see, thanks to much fund-raising by the British Museum.  It is currently operated by English Heritage, which provides audio wands to guide you through the rooms.

          Next to Darwin’s study, there’s his billiard room, where cause and effect operated on a simpler, more direct, level than it does in biology.

          Across the hall is the large dining room with its bay windows; it was also the “justice room” where Darwin served as a magistrate on occasion.

          The now-rebuilt stairway to the upstairs leads you to a series of former bedrooms, filled with modern exhibits about Darwin’s science.

          Darwin traveled into London for scientific meetings, but mostly he kept up an enormous correspondence.  His was something like the modern “home office” style of working, that computers and communications are making possible even for scientists without inherited wealth.  Darwin’s life shows you another style of doing science, one without classes to teach or students to supervise, without grant applications to write, one where piecing together the big story operated alongside the careful dissection of barnacles, digesting it all on yet another loop around the Sand Walk, carrying a great stick which he struck loudly against the ground, making a rhythmical click as he walked along with a swinging gait.

          It’s when making your own third loop around the Sand Walk (now pebble covered in the familiar English Heritage style, though there are still some flints to be found) that you find yourself wanting to tell Charles Darwin about all that has happened in the last 130 years, about how he was right about Africa being the place where humans happened.  Then you scale back your plans to something more suitable for the time it takes to make several more loops.  I decide on abrupt climate change, since it shows how you can have catastrophic gradualism.  

Imagine a world without Darwin.  Imagine a world in which Charles Darwin and Alfred Russel Wallace had not transformed our understanding of living things.  What . . . would become baffling and puzzling . . . , in urgent need of explanation?  The answer is: practically everything about living things. . . .

- Helena Cronin
The Ant and the Peacock
(Cambridge University Press 1992


Explaining things via catastrophes was seen then (as now) as a form of style without substance.  It was simply too reminiscent of miracles.  Gradual explanations were to be preferred, if they could be found.  Jerks were to be avoided.

          A nice algorithmic turning of the crank was, in comparison, a thing of beauty – and Darwin found a wonderful crank via his inheritance principle, where the more successful of the current generation were the ones who generated more of the minor new variants which future generations would test against their environment.  Variations on a successful theme was the name of Darwin’s game.

          Darwin saw that the climate had changed many times - he immediately offered some geological details to support Louis Agassiz’s 1837 notion of an ice age – and he assumed that animals and plants had to change too, to keep up with the times.  The variants more in tune with the new environment would reproduce better, in turn spawning yet more variants around their gene type (many variants, of course, are worse than their parents, but they don’t reproduce very well, what with high childhood mortality).  So adult body characteristics could track the climate, thanks to some novelties proving to be heritable.

          Efficiency improvements do, of course, result in the long run in a “lean mean machine,” where many features not used for a long time are stripped out as excess fat.  Until recent years, economists loved this view of things, with all its improving efficiency – until it became so apparent that it didn’t explain an innovation, only its subsequent improvement.  And in an economy dominated by market capture, where the first to market may overshadow a better late arrival, innovation is becoming much more important than efficiency.  It’s the “survival of the fastest.”  

The natural assumption, surely valid in some cases, is that climate will change slowly enough for little improvements to track climate over the generations – say, more and more upright posture as the blister-like uplift of the East African highlands helped convert forests into open woodlands and then savannas.  What I’d want to tell Darwin is that, just a decade ago, the ice cores revealed that there have also been very abrupt climate changes every few thousand years (on average; most are somewhat irregular exaggerations of an otherwise minor 1,500-year climate rhythm).

          These jumps are superimposed on the better-known gradual trends arising from variation in the earth’s orbit.  They are so large and so quick that a single generation gets caught, forced to innovate on the spot – innovate behaviorally, that is, since there is no time for anything in the gradual adaptations line.

          And this provides a way around the lean-mean-machine implications of traditional Darwinism.  Continuing to carry around a lot of useful-in-a-pinch abilities is a good thing when, about once in every hundred human generations, the climate goes mad for a while.  The variants that became lean mean machines didn’t survive very well in the crunch.

          Climate catastrophes are often mixed up with evolution­ary jumps (imagined macromutations and the like).  But when the climate catastrophes repeat so often, then a little one-percent change each time can jack us up, producing major changes in body and behavior in only a million years or so.  Darwin, I like to think, would have been intrigued by this “catastrophic gradualism“ insight. 







Janet Browne
Charles Darwin: Voyaging

(Knopf, 1995; Princeton UP pb 1996).  The best of the Darwin biographies (volume 1; the second volume is due in 2002).

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A Brain for All Seasons

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William H. Calvin