[From Bill Powers (960621.0900 MDT)]
Jeff Vancouver (9606210 xx) --
Of the two papers you sent me, I like the draft paper, "Some barriers to
constructing a unified theory of psychology," the better. The other
paper, on Goal Constructs, would be most meaningful to someone working
in the various fields that you cover, who is already familiar with the
literature or who would have time (and facilities) to go to the library
to find the meaning of a reference like (Beach, 1990). A person who has
not read the hundreds of references has only your word that what is in
each paper (somewhere) has something to do with the associated words in
the text, and of course no clue as to _what_ the referenced paper had to
say that was relevant. So I'm afraid that large parts of the paper
simply mean nothing to me (for example, "An action control theory
perspective on development is provided by Bandtstadter (1989)").
Basically, this sort of review paper is intended for those who only need
reminding of something they have already read. That's not me.
The "Barriers" paper, I thought, was a more constructive and focused
attempt to put PCT into the picture (although for me most of the
references are still meaningless). Perhaps I like it better because of
the number of times my name appears in it. But your basic theme is
certainly attractive to me: that all the scattered thinking about goal
phenomena would be better served if there were some unifying principle
behind it. Your explanation of how a hierarchical control system model
answers criticisms about "proactive" goal-setting was quite clear and
accurate. I appreciate your taking on Locke and his disgusting "Emperor
has no clothes" paper -- Mary and I have both written numerous versions
of replies to that paper, always ending up with "what's the use, he
doesn't want to know." Somehow I don't think your careful analysis will
make a dent, either.
The main problem I see in your approach is that what you're attempting
to do is probably difficult at best and maybe impossible. I think you're
trying to introduce a structural theory into a field where most of the
people don't have any idea what a structural theory is, or even that
such a thing can exist.
It doesn't take a great intellect to see that people have and pursue
goals, and of course you can look into goal-seeking phenomena in as much
detail as you please -- what goals people adopt, how experience
influences goal-setting and goal-seeking, and so on. But to me, none of
this answers the most important question, which is "What is a goal, that
it can be sought, and how, physically, can a goal have effects on
behavior?" The PCT model isn't just one more way of saying that people
seek goals. It's an attempt to answer the underlying question with a
working model -- a simulation of a real system -- that purports to
explain how the brain and body can behave in this way that we call goal-
seeking. The model that provides this explanation has features that show
us new relationships -- the relationship between goals and perceptions,
for example, or between actions and disturbances. These relationships
suggest new kinds of observations, and the model provides a new way to
make quantitative predictions. But basically the model suggests an
answer to a fundamental question that seems, in most of the literature
you cite, to be totally ignored.
What I fear is that your unifying approach will be taken by many as
reassurance that PCT doesn't offer anything they have to learn. "Why,
I've been speaking PCT all the time!"
The McClintock effect is the effect of the "menstrual synchrony" of
female friends and roommates. Somehow the sweat that woman secret
can influence the menstrual cycles of other woman. The result is,
apparently, new reference values for menstrual timing. Any ideas
of how this might be happening?
Sounds like a controlled quantity to me. The menstrual cycle is produced
by some kind of neurochemical oscillator, and oscillators can lock into
phase with each other if there are even small periodic influences of one
on another. But since pheremones occur in such tiny concentrations in
the air, I would suspect that there are sensors involved which amplify
the effects, and some sort of built-in circuits which provide the little
kicks to the oscillators. Not much new in that (See Hans Blom's reply of
96020). I've heard it suggested that there's an evolutionary
"explanation": that females, by becoming fertile at the same time,
improve their competitiveness for breeding. Of course that doesn't
explain _how_ they do it.
In human females, of course, there are all kinds of sensory indicators
other than pheromones to indicate that another woman is menstruating.
It's well known that cognitive-emotional factors can influence the
menstrual cycle. So why not say that for some reason, women (at some
level of functioning) adjust the phase of their menstrual cycles to
coincide with those of other women? Then the only question left is
Martin Taylor 960620 14:40 --
Very, very, early on, we tried to make clear that we UNDERSTOOD
that no ECS has any access to the disturbing VARIABLE, and that
ALWAYS when we used the word "disturbance" we were referring to
what came to be known as the "disturbing INFLUENCE." At no time
have I or Allan or Jeff (or anyone else of whom I am aware)
believed that the ECS or any aspect of it can have information
about the disturbing variable. And yet, when you want to show how
silly I am, you always start by asserting that I'm trying to
demonstrate the absurd proposition that the perceptual signal
contains information about the disturbing variable. And of course,
it's terribly easy to knock holes in that proposition.
Glad to hear it. Now all we have to do is unravel this fuzzy term
"influence," which has exactly the same problem as "disturbance," in
that the word can refer to the cause or to the effect. Television is a
bad influence on children; children's behavior shows the influence of
There you go, putting "disturbing variable" in place of what we
agreed on your deck in Durango should be called "disturbance
influence." You knew then, as you should have known earlier, and
certainly should know now, that we are well aware that they are not
the same thing.
Consider a rotary speed control that uses tachometer feedback. A torgue
applied to the turning shaft is a "disturbing variable"; the output
variable of the speed controller is also a torque. The sum of the
torques causes angular acceleration which is identically a change in the
angular velocity. So we have
brake ^ to velocity sensor
torque \ |
bearing torque ------> (integral of <-------- output
------> net torque) torque
The three disturbing torques add algebraically to the output torque to
generate a net angular velocity which increases or decreases with time,
ceasing to change when the net torque is zero.
By a convention on which I think we have agreed, each torque only
"influences" the angular velocity rather than "determining" it as would
be the case with only one torque acting. Each torque on the left is
also, by my usage of the term, a "disturbing variable" relative to the
velocity. So I make no distinction between "disturbance" and "influence"
in this case.
Where is the "influence" of which you speak?
Best to all,