PCT in a nutshell

[From Dag Forssell (950509 1420)]

I am glad Bill liked my "day's output" Thursday. I have polished
it some more, particularly the next to last paragraph. I am
submitting it again for critical review. Is there anything wrong
or misleading about my characterizaiton of PCT, conventional
science, and behavior? I am incorporating this in the PCT resource



                       PCT IN A NUTSHELL

The most obvious phenomenon of life is this:

         _We act to make our wants come true_.

This phenomenon can be seen in ourselves and all around us all the
time -- ranging from very short to very long time frames:
milliseconds to years.

o You want to bend a finger: You bend it.
o You want to draw a circle: You pick up a pencil, sharpen it,
   place a paper on your desk -- and draw a circle.
o You want a college degree: You apply, take classes and tests,
   sustain yourself and persevere -- and get your degree.
o You want to develop a product: You ------ and the product is

Perceptual Control Theory (PCT) provides the first explanation for
this pervasive phenomenon of "self-direction" or "control" that can
stand up to scientific scrutiny. When you understand the details
of this technical explanation, you understand how autonomous
control is synonymous with freedom and gives rise to conflict or
cooperation -- depending on what is wanted, how it is perceived, by
whom and to what degree. A brief summary of PCT:

You continually _compare_ the mental image of what you want, your
purpose, which we call a _reference perception_, with the
corresponding mental image of what is, which we call _present
perception_. From this comparison emerges a _difference signal_
(corresponding to dissatisfaction) which causes _action_ -- your
means to _influence_ your world and your _present perception_ of
it. Effective action causes this present perception to conform to
the reference perception. Action ceases when your present
perception agrees with your reference perception.

The net result of this circular loop of interacting elements and
signals is that a self-directing "living control system" controls
its present perception so that it agrees with the internally
specified reference perception. The living control system shapes
its world the way it wants to perceive it and keeps it that way.
When _disturbances_ (external influences, stimuli) affect something
the living control system has a reference perception for, it will
act to restore its perception (resist the disturbance, response).

Conventional scientific attempts to explain behavior have not
recognized or clearly understood the obvious phenomenon of control
discussed above, and are misleading. Behavior is neither just
caused by stimuli in the environment nor is it blind execution of
internal plans. Behavior is not an end result. It is an integral
part of the closed loop process which controls perception--the
phenomenon of control. As can be seen from this summary, the
explanation for the phenomenon of self-direction or control
includes an explanation for the appearance of stimulus-response,
but without the notion that the organism is conditioned or
reinforced; that the behavior is shaped or that it is motivated by
reward or punishment. It also includes an explanation for the
appearance of plan-execution, but without suggesting blind

With an understanding of PCT, most of the present day mysteries of
human behavior can be seen for what they are: manifestations of
self-direction or control, given a wide variety of reference
perceptions, present perceptions, circumstances and external
influences in the world where autonomous living control systems
interact. The mysteries simply vanish, and the terminology that
went with them becomes irrelevant.

                      Dag Forssell May, 1994

Comments solicited, Best, Dag