(Note: I'm re-sending this because I got no acknowledgement when I first
sent it last Monday --Ted)[or again earlier today]
If you Google "define:behavior", you get a list of two dozen or so
definitions found on the web, none of which meet the criterion of explaining
how behavior works.
I'm becoming more and more convinced that PCT is the only theory of behavior
as such. The other entries are dictionary definitions and statements about
behavior acquisition.
And most of the definitions would include the movement of the toothbrush
robot as behavior, thus revealing their vacuity:
http://theradula.blogspot.com/2008/03/cute-fun-but-needs-onoff-switch.html