acceptance of PCT

CSGnet Archive CSG1994
1

[From Bill Powers (940811.0615 MDT)]

Paul George (940810.1500) --

I'm following your conversation about PCT research and acceptance at the
same time I'm working on a paper that compares the inverse-
kinematic/dynamic model of arm control with a PCT model. It seems to me
that our problem goes much deeper than that of merely gaining
acceptance.

There is something seriously wrong with a science that could accept the
idea that the brain achieves organized behavior by computing the joint
torques that will produce it. To do these computations, the brain
requires information about the masses and moments of inertia of the arm
segments, the properties of muscle contraction both static and dynamic,
the properties of nonlinear muscle springs, the variations in mechanical
advantage as the joint angles change, the physics of dynamic movements,
the trigonometry of spatial relationships, the location of targets in
visual space, and the initial state of the arm in terms of positions and
velocities relative to a possibly moving target. The brain is required
to do computations involving signs and cosines, multiplications and
additions and divisions and subtractions -- and to do all this in real
time with so much precision that after a double time integration, the
final result is the kind of pointing accuracy we observe in the real
system. The body is assumed to be as stable as a rock, the muscles to be
immune to fatigue, and the environment to be free of unpredictable
disturbances.

There is an air of dreamlike unreality about this model. It is assumed
that anything a mathematician can do with pencil and paper and symbols,
the brain can do with neural currents (without symbols). It is assumed
that all the knowledge that external observers have obtained in 300
years of studying the physics and geometry of the arm and environment is
available in real time to the neural computers, even those of a monkey
or a mouse. Just how this information becomes available is not even
considered.

So the question naturally comes to mind, "Why should PCT researchers be
interested in acceptance of PCT by people who could bring themselves to
believe in such models?" Just what would such people be accepting?
Another abstract mathematical scheme with no more justification than any
others they have believed in? Another form of magic? Another kind of
prediction that is true some of the time, for some systems, under some
conditions? Is there the slightest chance that they would grasp PCT and
use it as a real theory? Or would they just use it as another
"perspective" on nature, to be adopted or not at one's convenience?

PCT does not explain all behavior of all organisms, just as physics does
not explain all behavior of all matter. But the failures of explanation
are of a kind different from those found in psychology. They aren't
statistical; they are total. There are phenomena that we simply don't
understand, and we know we don't understand them. There is no point
pretending that we do understand, until we actually do. What psychology
is missing is a concept of this point of understanding where you are
simply backed into a corner, and no matter what alternatives you may
think of you are continually forced back to the same view. Everything
else is ruled out. If there is a better explanation, and one knows there
will always be a better one some day, it is simply not available now.
The trail, for now, ends here. When we reach such a point of
understanding there is no choice but to proceed as if it is true.

The kind of understanding that comes out of psychological theories is
the same kind one could obtain with an understandingness pill, like the
sense of godlike comprehension that some people seem to get from
cocaine. It is a decision to believe rather than to look further.

Psychological theorizing does not stop when there is no other place left
to go; it stops when an already weak sense of skepticism about one's own
ideas is completely suspended. So we have dozens of competing
"microtheories," all existing at once and all accepted as part of
psychology, and hardly a one destined to last more than five years.

Is this the field in which we aspire to gain acceptance?

ยทยทยท

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Best,

Bill P.

2

[From Rick Marken (940811.2020)]

Bill Powers (940811.0615 MDT)--

It seems to me that our problem goes much deeper than that of
merely gaining acceptance.

Indeed.

The kind of understanding that comes out of psychological theories is
the same kind one could obtain with an understandingness pill,

The only drug that's still legal in the US :wink: Notice how legalization
curbs violence. Plus, we don't have the dealers and users messing up
our neighborhoods; they tend to remain in approved understanding-
ness distribution zones -- better known as social science and busness
departments of universities.

Is this the field in which we aspire to gain acceptance?

Of course we do;-) But the worst part is that sometimes we ARE
accepted. I just received two papers from Jeff Vancouver, both co-
authored by Robert Lord and both rather accepting of control theory
and Powers' use thereof (at least, as they understand it). In one article
(Campion and Lord, 1982), acceptance of Powers' control theory model
of behavior is rather explicit. Unfortunatly, it is also based on a rather
superficial undertsanding of how control systems work and what
control theory is about. Campion and Lord begin by presenting a
diagram of a control system that could not possibly work (the reference
signal depends on the error signal, for some myterious reason). They
then proceed to test this model using conventional psychological
methodology, reporting only group averages and having their
hypotheses confirmed with significant (at the .001 level) correlations
that never exceed 0.37. The later paper (Kernan and Lord, 1990) also
seems to "accept" Powers' version of control theory -- and it was just
ss bad as the first, theoretically and empirically.

It was really difficult to read these papers. Both are waste deep in that
old-time social science (both papers are published in what seem to be
relatively major organizational psychology journals) wraped up in bits
of PCT language. I felt sorry for the authors, really; with a little
more patience and humility they could have savored the rare, sweet
delights of PCT. Instead, they seem to have settled for gorging
themselves on the abundant, bland pablum ("understandingness") of
conventional behavioral science.

With acceptance like this, who needs an emetic?

Rick

3

Richard:

    In your recent posting, you stated:

It was really difficult to read these papers. Both are waste deep in that
old-time social science (both papers are published in what seem to be
relatively major organizational psychology journals) wraped up in bits
of PCT language.

    I note with delight the phrase: "waste deep." A slip of the
fingers, I assume, but what a lovely slip! Perhaps you can try to
popularize that metaphor.

    Best wishes,

Lewis Henry LaRue
Washington and Lee University
School of Law
Lexington, VA 24450

e-mail address: LHL@FS.LAW.WLU.EDU
telephone: 703-463-8513

4

Tom Bourbon [9400812.0833]

[From Rick Marken (940811.2020)]

Bill Powers (940811.0615 MDT)--

Bill:

Is this the field in which we aspire to gain acceptance?

Rick:

Of course we do;-) But the worst part is that sometimes we ARE
accepted. I just received two papers from Jeff Vancouver, both co-
authored by Robert Lord and both rather accepting of control theory
and Powers' use thereof (at least, as they understand it). In one article
(Campion and Lord, 1982), acceptance of Powers' control theory model
of behavior is rather explicit. Unfortunatly, it is also based on a rather
superficial undertsanding of how control systems work and what
control theory is about. Campion and Lord begin by presenting a
diagram of a control system that could not possibly work (the reference
signal depends on the error signal, for some myterious reason).

That is precisely the kind of uninformed change you find in most of
the Pop PCT articles, the ones so readily accepted by editors and
reviewers. I know from personal experience with Lord that he hasn't the
slightest idea why such changes are wrong. Not merely different from some
"PCT dogma," but wrong. A model constructed like that doesn't work the way
he thinks it would. But that's the advantage he gains by not working with
models; he remains free to ignore the fact that he is wrong, then to go
ahead and do what you described next:

They
then proceed to test this model using conventional psychological
methodology, reporting only group averages and having their
hypotheses confirmed with significant (at the .001 level) correlations
that never exceed 0.37. The later paper (Kernan and Lord, 1990) also
seems to "accept" Powers' version of control theory -- and it was just
ss bad as the first, theoretically and empirically.

Traditional "behavioral science" grafted onto a silly rendering of PCT. And
*that* is what we are supposed to emulate? Those are the people from whom
we are supposed to seek acceptance? No thanks.

It was really difficult to read these papers. Both are waste deep in that
old-time social science (both papers are published in what seem to be
relatively major organizational psychology journals) wraped up in bits
of PCT language.

I love the pun: waste deep! In the spirit of Woodstock '94, Write on!

I felt sorry for the authors, really; with a little
more patience and humility they could have savored the rare, sweet
delights of PCT. Instead, they seem to have settled for gorging
themselves on the abundant, bland pablum ("understandingness") of
conventional behavioral science.

Yes. But Lord had a chance to watch and learn about PCT modeling a couple
of years ago, at a meeting where I was running demos as part of a poster
presentation. He looked at them for a few minutes, then walked away. I
guess I was working at the wrong levels in the hierarchy -- the ones where
you can see immediately that his ideas don't work and that he is not talking
about PCT at all.

Later,

Tom