Patricia writes:
> I have experiences teaching children about reptiles, and I think the fear
> factor is largely learned, but sometimes for good reasons. A while back I
> had a classroom of 6th graders in my zoo educational building at the Bronx
> Zoo. I brought in a python, and all the kids got excited, until they heard
> the chaperon mother shriek at it and they all copied her. It was a sad
> lesson.
It's also the most natural of reactions.
Every bit of evidence indicates that we and the other primates have a deep
instinctual fear of snakes, but oddly enough, the evidence also indicates that
the expression of that fear has to be first socially triggered by having a
member of the troop (or a chaperon mother) first shriek at the sight of the
snake,
making the fear of snakes the oddest of reactions, passed generation to
generation partly within the content of the lineage's germline DNA and partly
outside genetic inheritance, through social learning.
What follows below are a few comments Matt Ridley had on the subject:
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The classic and best experiment in this is Susan Mineka's work with a group
of monkeys in Madison in the '80s, where she set out to examine the ontogeny of
an instinct â in this care fear of snakes. Wild-born monkeys are afraid of
snakes. They're so scared of snakes that they will cower in the back of the
cage
screaming rather than reach across a plastic model snake to get at a peanut
when they're very hungry. Captive-born monkeys are not afraid of snakes; they
happily reach across the model snake to get at a peanut.
So what's going on here? That means that fear of snakes must be learned. But
how on earth do you learn fear of snakes? The conventional classical
conditioning wouldn't work very well, would it, because either you have a bad
experience with a snake to learn from, in which case you're dead, or you don't
have a
bad experience, in which case you don't learn that snakes are frightening. So
how are you going to end up acquiring a fear of snakes?
It seems an absurd thing to acquire. She argues that what's happening is that
there is a program for fear of snakes, an instinct if you like, but that that
instinct needs to be socially triggered â in some sense triggered by a
vicarious experience, by observing another monkey having a fear of snakes.
So she set up an experiment in which she videotaped the wild-born monkey
reacting with fear to a snake, and she then showed this video to a captive-born
monkey, which immediately acquired a fear of snakes and was not then prepared
to
reach across even a model snake to get a peanut.
She now doctors the video, so that it has the same monkey reacting in the
same way in the background, but the bottom half of the screen now instead of
having a snake has a flower. Again, the captive-born monkey has never seen a
flower, so after it sees a monkey reacting with extreme fear to this new thing
called a flower it should just as easily learn a fear of flowers.
But it doesn't. It just learns that some monkeys are crazy. So what's going
on here is that there is clearly an instinct for fear of snakes, and that's not
surprising. Human beings have snake phobia. It's the commonest of all the
phobias, even though most of us hardly even ever see a snake in our lives, but
it
requires an input from the environment. It requires a nurture input to be
triggered.
We know this is happening in the amygdala, and we're getting a bit of a
handle on which cells are involved. We're not yet down to the gene level, but
I'd
bet my bottom dollar there's going to be a little pathway of genes in here
that's mediating this process.
-- http://www.edge.org/3rd_culture/ridley03/ridley_p5.html
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Wirt Atmar
