‘Scientism’ is not a valid critique of Psychology as a science, but a snarl word flung around by those with an inadequate understanding of the field.
Science, is not a thing but a methodology, philosophy, intellectual approach.
Anyone taking the popperian approach to investigation of a subject or field is, by definition, a scientist (at least in Western philosophical terms).
Poor practice by individuals, does not reflect upon the field but upon those individuals.
Not all those claiming to be psychologists will be good ones. Not all those claiming to be psychologists will be scientists. Some will engage in pseudoscience. It does not, however, spring axiomatically therefrom that Psychology is ‘scientism’ and to claim that it does is no more than recourse to the post hoc ergo propter hoc fallacy.
Finally, Scientism is not what most people think it is …
https://rationalwiki.org/wiki/Scientism
Your critique of the failings of IQ tests as a measure of the phenomenon they claim to measure, or even the very existence of the thing they claim to measure … whilst, perhaps, valid and aposite … can not be expanded to critique the whole field of study of which they form a part — to do so is to fall prey to the Inductive Fallacy, whereby a conclusion is drawn from premises that only lightly, if at all, support it. Moreover, it is, further, Begging The Question inasmuch as the a priori assumption that Psychology has a ‘sinister track record’ is drawn from no evidence hitherto supplied in the argument.
Your critique of the use, even the basis for, IQ might well be right … and any good psychologist will be aware of its history and inherent failings and, therefore, likely agree with you, up to at least a point … but the argument that the discipline of Psychology is ‘scientism’ is not valid on that basis and is, furthermore, not so even allowing for the pejorative use of the term ‘scientism’ in that you critique it for not being scientific … which is tautological (or at east self-contradictory) inasmuch as your argument is based upon the principal that the scientific method is itself valid — either the scientific method is the yardstick for enquiry or it is not, but it cannot be both and the snarlword use of the term ‘scientism’ is, therefore, no argument at all in this instance (or, indeed, ever so).
