[From Bruce Abbott (951011.2350 EST)]
Bill Powers (951009.2025 MDT)
I'm feeling discouraged again. Your message to me is that a good start
has already been made toward a PCT model of behavior (particularly in
the area of work in which you have a large investment), that the sound
scientific methods that have been used need no modifications, and that
everything that has been concluded so far about behavior is probably
correct, as far as it goes. The behavioral sciences have been getting
along just fine without PCT, so the most that PCT can offer is a few
interesting perspectives.
If this is the message you have been receiving from me, it is certainly not
the one I thought I was sending, and given your interpretation, I also am
feeling discouraged and more than a little depressed over this result. If I
thought any of those opinions you attribute to me were true, I can't imagine
why I would give more than two seconds of thought to PCT: after all, we're
doing just fine without it and all it "can offer is a few interesting
perspectives." What you have described sounds more to me like the kinds of
things you've heard from those reviewers and critics who have used such
phrases to explain why they have decided to reject your paper, or your
viewpoint.
When you say that some controlled variables have already been
identified, I simply can't believe that. I don't believe that there was
any systematic effort to apply disturbances and measure the difference
between the effect expected under the hypothesis of no control and the
observed effect.
I'll try to find the reference for you. As I recall, the study examined the
following behavior of chicks or ducklings or goslings (I don't remember
which) that had been imprinted on an object whose motion could be readily
controlled by the investigator. (It was mounted on an arm extending from a
central pivot, which moved the object in a circular path through a circular
corridore.) The imprinted birds followed the object as they would have
followed their natural mother under normal circumstances. However, the
situation was then changed so that when the birds ran toward the object, it
retreated from them faster than they could approach, and when they ran away
from the object, it approached them faster than they were retreating. After
some experience with this arrangement, the birds learned to move in the
direction that would keep them within a specific distance from the object.
At least this is my recollection of a second-hand account of the study.
Other studies have examined the conditions under which imprinting/attachment
develops, what changes in behavior occur during separation and immediately
following reunion, what happens to the young animal if reunion never occurs,
what happens if attachment fails to develop, and many others. Perhaps the
best presentation of this subject (even though now years behind the
research) is still the classic, John Bowlby's (1969) _Attachment and Loss_.
You would find especially interesting the part wherein Bowlby describes how
the newborn's open-loop crying (the intensity of the crying does not vary
with perceived distance to caregivers, nor does the quality of crying vary
with the cause) soon develops into a closed-loop form as the infant's
nervous system matures and it begins to learn from its experiences. Another
area of interest is Bowlby's description of the young child's attempts, with
difficulty, to keep stride with the adult who is holding it by the hand. I
don't know how familiar Bowlby was with control theory, but he knew control
when he saw it, and he correctly described its closed-loop, negative
feedback, error correcting character.
I don't believe that there was a systematic effort to
identify the output variables that affected the controlled variable and
the paths through which the effect occurred, or the actual pathways by
which the state of the controlled variable could be perceived by the
organism.
Output variables in chicks: peeping, movement. Peeping affects proximity
through the action of the mother hen's control system, movement by closing
the distance between visual representation of mother and (I believe) her
sounds; pathways: visual, auditory. Additional inputs: sensation of warmth,
physical contact with mother or others in brood (speeds restoration of error
to zero): pathways: somatosensory.
I don't believe that any models were set up to test the
predictions of the control hypothesis, or that standards were set such
that the predictions had to be right almost all of the time.
As to the former, see description of study above. As to the latter, no, no
modeling was done.
Words fail me. I don't think you see that all of your explanations and
defenses look to me like the same stone wall that I've been butting my
head against as long as I can remember. I don't think you see why, when
you bring up studies like the chick studies with MSH, I just want to
throw up my hands and abandon the whole thing. Before I come to the
final end of my stores of patience and persistence, I want to know that
somebody else understands what could be done with PCT, starting from
scratch. A few do. Most don't. You don't seem willing to start from
scratch. I can't see any other way to do the job right.
Even Copernicus didn't demand that astronomers throw away their laboriously
and meticulusly assembled maps of the heavens and start from scratch. Their
conceptions, yes; the observations, no. You can't see any other way? It
seems to me that the phenomena of attachment and loss, extending as they do
from lowly chickens clear across to the human child and parent, have already
demonstrated their dependence on specialized control systems designed by
evolution for the purpose of keeping the child safely within its parents'
protective influence. The benefits of this analysis are already being
widely felt in clinical and other applied settings. It absolutely
astonishes--and saddens--me to hear you say that you think such research is
antithetical to PCT.
I suggest you read Bowlby's (1969) book and see whether I doesn't change
your opinion.
Regards,
Bruce