Those fields you mention can all design tests which can be verified. Can Psychology? Can psychology measure anything, put things in the form of laws and equations?
It´s not about being short of one criterion. It´s about lacking most of them.
Much of psychology can do this. Sadly, but not surprisingly, not all of psychology can.
Psychology is, as I tell my History of Psych students, the bastard child of three parents. It combines the questions of Philosophy with the methodology of Science...but there is also in the family tree of psychology the remnants of witch-doctors, mesmerists, exorcists, and con artists. I am perfectly serious. Whereas the scientific branches of psychology saw Freud as unscientific, Freud still represents psychology to a segment of the population. A typical bookstore has a "psychology and self-help" section that is as much--no, more--horsefeathers as science. Even clinical psychologists... there are too many whose practice is driven by theory rather than by evidence.
It is as if (to switch sciences) the popular view of physics was represented by "what the **** do we know?". Worse, actually--it is as if the view of physics,
even to other sciences, was represented by that terrible movie.
There is a chasm between the popular view of any science and the actual research of the science itself. It does not behoove us to act as if the public view of the science is accurate. We know better.
Physics is so much more than "what the **** do we know?" Psychology is much much much more than Freud, or Jung, or "Men are from Mars, Women are from Venus"*, or "I'm OK, you're OK", or Doctor Phil.
Can psychology measure things in the form of laws and equations? Yes, yes, a thousand times yes. Learning curves, extinction curves, the matching law, the Rescorla-Wagner model (behaviorism), Ebbinghaus's forgetting curves, serial position effects (memory), [at this point, faced with everything from psychophysical data on sense organs, to social facilitation and loafing effects in groups, to all of cognitive psychology, to cognitive neuroscience, to biopsychology, to developmental, I gave up on individual mathematical equations]. [Sadly, I did note that much--fortunately, not all--of clinical psychology, and much--again, not all--of popular psychology, was immune to such treatment. It is understandable, if ignorant, that some might think that all of psychology was so poorly evidenced.]