Often, in normal vernacular, social sciences — especially psychology, sociology, economics, and anthropology — are “soft,” and natural sciences — especially physics, chemistry, and biology — are “hard.” This is then generally used to deride the “soft sciences” with the connotation that softness denotes an inherently negative or less significant field of study. This usage is particularly prevalent among those who fancy themselves as falling under the “hard science” category in a way that denigrates social science.
There are implicit and sometimes strongly explicit suggestions that “soft sciences” are less legitimate or less scientific fields. Amusingly, there isn’t even consensus on what determines the relative “hardness” of a scientific field of study. Some relate “harder” science to more precise predictions, while others denote it as tied to complexity — “softness” here being synonymous with simplicity. Ideally, as the scientific method is what we refer to when discussing scientific fields, relative “hardness” would in some fashion relate to how often and how well a field uses the scientific method.
The origin of this hierarchical concept arose from Auguste Comte, a French political philosopher from the first half of the 1800s, who was anticipating the rise of social science.
Comte had set out to create a hierarchy of the sciences, to unify understandings around scientific principles, and to put forward sociology as an important field of future study. His intent was never to classify social science as less than the others, but rather a differing range of complexity of phenomena and generality/complexity of measuring instruments. Methodology in studies that argue for “hardness” as an important measure often make use of questionable measurements, such as “impersonality … indexed by the frequency that only first initials are used in footnotes” (Storer, 1967).
As noted by “Bibliometric Evidence For a Hierachy of the Sciences,” those who more recently argue for hierarchy in the sciences discuss entirely different implications, and specifically decry the “simplistic dichotomies” that have been created by “hard/soft” science. Hierarchy of sciences and “hardness” are distinct, and the former is philosophically important, while the latter is not.
Frustratingly, the connotation of the social sciences as being markedly easier than the natural sciences has other roots. Notably, relative rigor in undergraduate degrees is often cited — or at least implied — as one distinction which clearly favors the natural sciences.
However, unlike an engineering student who graduates with a bachelors degree and 13 years of pre-collegiate mathematics experience, a psychology major has been given little, if any, prior education in the matter and proceeds to a higher degree/certification level for a comparable vocational position.
This is particularly irritating as it relates to psychology, which is as diverse a field as any of the broadest natural sciences. Just as physics permeates all areas of life, psychology is tied to anything in which there is human involvement in any capacity. Thus, it is not only oversimplified, but also exceptionally ignorant to assume that one can classify entire diverse disciplines in this dichotomistic fashion without considering the specific fields present in those disciplines.
If one would like to create a hierarchy within specific topics of research, that is a separate discussion, but that is not the way these distinctions are made in common vernacular — nor among those who attempt to discredit social sciences by calling them “soft.”
“STEM” — being the classification of fields: Science, Technology, Engineering, Mathematics — is another blanket method of somewhat arbitrarily disparaging social science because the negative perception of social science makes it somewhat distinguished from natural sciences in this arena as well. Psychology is currently not consistently recognized as a core STEM discipline.
Social science is not perfect, and it contains areas that are in need of change. There are flaws in null-hypothesis testing that must be addressed, and these are relatively young fields to begin with. However, not being taken seriously as a discipline means that STEM funding is diverted away from social science fields, creating a self-perpetuating system where social science is continually devalued and defunded. To put it more pragmatically, there is marginal practical value to be found in the “hardness” argument, but notable societal detriment.
The utility of the concept lies in some vague conception of how useful or reliable a branch or field of study is, and this can be recognized and classified through other means that actually provide a useful result — like an evaluation of methods used or an application outside of experimental settings.