Behavioral illusion

[From Bill Powers (930920.1130 MDT)]

Dag Forssell (930918.0025), Rick Marken (930917.1100) --

The "behavioral illusion" that I have talked about is the
relationship between the disturbing variable and the output
action of the control system, not the one between perception and
output (the perception is invisible to the onlooker).

The appearance is that a distal stimulus acts generally on the
senses of the organism to cause a response, a change in output
action. This is an illusion when it omits an actual controlled
variable. The controlled variable begins to change when the
distal stimulus event acts on it, but the output action
immediately starts to change to have a nearly equal and opposite
effect on the controlled variable. Most of the effect of the
distal stimulus on the controlled variable is cancelled, so the
effect on the senses is far less than it would be if there were
no feedback effect.

There's no _a priori_ way of proving that a behavioral illusion
is in effect. The only way to prove that there is an illusion is
to demonstrate that there is in fact a controlled variable being
affected as above. If there is no controlled variable found, then
there is no illusion and the S-R interpretation may be correct.
PCT doesn't automatically prove that no S-R connections exist. It
simply tells us what to look for to see whether such a connection
exists. So far our experience has been that apparent S-R
connections all involve a controlled variable, and so the S-R
connection is an illusion. However, the next experiment one does
may show that there is no controlled variable and hence that the
S-R interpretation is preferable to the PCT explanation.

The more S-R connections we can show are really illusions, the
more justification there is for assuming that the next apparent
S-R connection we see will also be an illusion. But that sort of
extrapolation from past experience doesn't justify saying that
ALL apparent S-R connections are illusions. Neither are we
justified in simply making up a possible controlled variable to
turn an S-R explanation into a PCT explanation. That change
remains only a possibility until the actual experiment is done to
test for the proposed controlled variable. Until we can point to
a persuasive tested candidate for a controlled variable, all we
can say is that the PCT explanation is a viable alternative to
the S-R explanation.

What we want, I think, is not to convince believers in S-R
explanations that they are full of hogwash, but only that there
is a viable alternative and a way of choosing between the
alternatives. If the method for determining the presence of a
controlled variable can be taught and accepted as a valid method,
that is all we need. If, as we have reason to suppose, nearly all
apparent S-R connections actually involve controlled variables,
then even an S-R enthusiast can apply the test to see whose
convictions are the more firmly grounded, in any particular
instance of behavior. I think our thrust should be toward getting
the Test accepted as a valid methodology; the rest will then take
care of itself.

Best,

Bill P.