What can "straighten out" the mess that psychology is? I believe it is by coming to realize that SEVERAL basic assumptions (actually, just totally unproven beliefs) are incorrect and the opposites are true.
You will see much/most of the following is the OPPOSITE of what your psychology professors tell you, but it can clearly be argued that all of the following are more in line with biology (organismic, if you like):
(1) one should develop a theory expressly consistent with biological principles (e.g. homeostasis) -- it should clearly and, in effect, constantly show in the theory;
(2) The most significant learnings and innate factors occur, in effect, completely simultaneously (and the innate factors at times may well be more important, regardless of the stage of development one is looking at);
(3) Major innate guidance emerges with each significant qualitative advance in conceptual abilities (last one around adolescence, at the earliest);
(4) The more "advanced" the organism, the more learning occurs, BUT ALSO the more [significant] innate guidance (factors) are involved;
(5) Inductive work should be emphasized and hypothetico-deductive systems should be formulated ONLY when you must (and then with no loss or bias of/in observation)
(6) Everything that develops, including our most prized abstract conceptual abilities, are very likely and potentially observable, concrete (in their inception) -- and likely seen as perceptual (perceptual/attentional) SHIFTS and adaptive biases. (This is the empirical assumption and the way it would happen with the organism adapting in its environment. NO abstract conceptual abilities emerge from just internal processes -- from just "thinking" in the brain/mind. )
None of the above indicates there is less learning (more if anything); but, there is no "pure" learning.
Seeing things this way totally frees one to be a thorough-going empiricist and to DISCOVER answers with key real-time observations of the subject. THIS "straightens out" psychology. The Subject can begin to provide the definitions and the related-definitions; research becomes a MUCH more inductive process.
It is true that some research may involve the new eye-tracking technology and software (but we have that now).
See especially: https://www.researchgate.net/publication/286920820_A_Human_Ethogram_Its_Scientific_Acceptability_and_Importance_now_NEW_because_new_technology_allows_investigation_of_the_hypotheses
Article A Human Ethogram: Its Scientific Acceptability and Importanc...