"through examining behaviour"
This is the very nature of analysis. Objectivity itself is derived from subjectivity.
Within the scientific realm, objective medical analysis of "illnesses" is performed by simply comparing physical/psychological characteristics of a given individual to data from average, "healthy" individuals.
The chemical analysis that you refer to is suited for a medical science discipline such as Neurology.
Recognizing that aspect does not make "psychology" pseudo-scientific. It merely requires accepting a different set of criteria. |