@empiricism,
You don't understand the words "just as".
You are the one with the security blanket.
Speaking as a published experimental psychologist I can state the following :
Behavioral psychologists
mimic being physicists in order to don a cloak of "scientific respectability". But the problem of "the observation of observation" which is central to all considerations of "a stimulus", has major practical and philosophical implications, and has given rise to such fields as "second order cybernetics" (Von Foerster) which rejects your reductionism.
Furthermore, so called "testing" merely involves the rejection of a null hypothesis at some
arbitrary "significance" level, and quite often particular tests are chosen or assumptions made, to produce such "significance".
Rejection of a null hypothesis is quite different to
supporting a theoretical framework which directs data collection. Psychologists also have the problem of extrapolating from the artificiality of the laboratory to "real life" since their very act of opening an experimental "window on events" can have the same effect as the Heisenberg uncertainty principle in affecting "the data".