# Behavioral illusion **URL:** http://discourse.iapct.org/t/behavioral-illusion/1653 **Category:** CSG1993 **Created:** [September 20, 1993, 6:06pm UTC](http://discourse.iapct.org/t/behavioral-illusion/1653 "1993-09-20T18:06:14Z") **Posts on this page:** 1 **Page:** 1

### Author: ![William\_T\_Powers2](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/w/c67d28/32.png) [@William\_T\_Powers2](http://discourse.iapct.org/u/William_T_Powers2) #### Post date: [September 20, 1993, 6:06pm UTC](http://discourse.iapct.org/t/behavioral-illusion/1653/1 "1993-09-20T18:06:14Z")

[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.