Re: Anthropology and Prediction

Ruby Rohrlich (rohrlich@GWIS2.CIRC.GWU.EDU)
Mon, 11 Sep 1995 21:45:39 -0400

Timothy Ferisin his rev iew of Murray Gell-Mann's *THE QUARK AND THE
JAGUAR: Adventures in the Simple and Complex* concludes thusly: " For
many readers, the best thing aout "TheQuark and the Jaguar* is not so
much its discussion of technical issues as the way it conveys something
of the excitement and majesty of the quantitative, scientific way of
looking at things. Certainly Gell-Mann's passion for living things helps
to explain the bare-bones equations that scare so many people away from
science. In a characteristic passage, Gell-Mann notes that the
ornithologist Charles Munn, studying feeding flocks in a tropical forest
in Peru, found that they typically are accompanied by 'sentinel' birds
that call out to warn of approaching raptors. Sometimes the sentinels
make false calls: "The fake alarm often permitted the sentinel to grab a
succulent morsel that another member of the flock might otherwise have eaten.
"Careful observation," Gell-Mann writes, "revealed that the sentinels were
practicing deception about l5% of the time and often profiting by it. . .
. Presumably, if the percentage were much higher, the signals would not
be accepted by the rest of the flock and it if were much lower, the
opportunity for the sentinal to obtain extra food by lying would be
partially or wholly wasted. "I am intrigued by the challenge of deriving
b y some kind of mathematical reason the figure of about l5%," he
continues. "In a plausible model, might it come out one divided by two
pi?" When I asked that question of Charles Bennett, the UCLA ecologist,
he was reminded of something his father had told him about Royal
Canadian Air Force units based in England during World War II. They
found it useful when sending out a fighter and a bomber together, to
attempt occasionally to deceive the Luftwaffe by positioning the fighter
below the bomber rather than above. After a good deal of trial and
error, they ended up following that practice at random one time in seven
-- in other words, ab out l5% of the time. I don't know whether
Gell-Mann the birdwatcher sees tongues in trees, but there is something
more than a little charming in the notion that he sees birds as
mathematicians." I also found the notion more than a little charming.
Ruby Rohrlich.

On Sat, 9 Sep 1995, John Mcreery wrote:

> Broadly speaking, I am in full agreement with recent remarks by Matt Tomaso,
> Bob Graber, and Mike Carson. To be human is to predict. I reach for my cup of
> coffee and I am, ipso facto, involved in predictions. The cup is real--not an
> illusion. There is coffee in it. I have sufficient control over my hand to
> grasp and lift it. The shattering effects of living in an unpredictable
> universe are all to evident if the cup turns out to be an image in a mirror,
> what I thought was coffee turns out to be motor oil, or, suddenly afflicted by
> a stroke, I find that I can no longer control my hand.
> When I do any form of research,I find myself predicting constantly. I ask a
> question of a friend/informant/author of the book I am reading. I anticipate an
> answer which falls within a certain range of linguistically and culturally
> acceptable responses. When my prediction fails, I look for reasons why. My
> question was ill-formed, my grasp of the language and cultural rules in play
> was flawed, the person I am questioning is flawed in some similar or, perhaps,
> dissimilar way. If the occasion is a Chinese banquet and my informant chokes and
> starts to turn blue immediately after I pose my question, it is altogether poss
> ible that s/he is choking on a bone and a Heimlich maneuver is in order. That
> the fish was poisoned is another but more remote possibility.
> Could it be that the issue is not whether we predict but HOW we predict?
> Consider a simple physical case: water turning into ice.
> A says, "Water freezes when it gets cold enough."
> By says, "Water freezes when the temperature reaches 0 degrees celsius."
> C says, "The shift in phase from liquid to solid which occurs at 0 degrees
> Celsius is a consequence of quantum dynamic relationships between the elements
> hydrogen and oxygen that result in molecules with a characteristic shape (I'll
> stop here, my ignorance is all too obvious.).....
> If we imagine a universe in which predicted relationships are, as I mentioned
> before, linear, curvilinear, chaotic, complex, etc....Where to anthropological
> predictions stack up? Could this be the real question?
> Yours truly,
> John McCreery