Why does that matter, if it is done to help understand how certain traits, measured in large quantities, affects other quantities?Psychometrics on "intelligence", "personality", and other complex things like that, I find futile. I think we will miss too many "corner cases" taking statistical apporaches.
Take criminology, for example. Is it pointless to attempt to derive the main factors that drive crime?
So suggest the better way of discovering truth...? Use the criminology example - how would you do "factor analysis" without doing "factor analysis" to see the contributions to general crime rates (and types of crime). It's one of the most complex things I can think of, in terms of social sciences, so if there is a better way of doing it, I'd be very interested.To see how real science is done on complex systems, look at modern biology. The discovery of DNA, its structure, what genes actually express, etc.
For a slightly older version, you could also look at the development of chemistry (for the more macrascopic ideal gas laws, to the periodic table, to P-chem (quantum mechanical modeling, and approximations based on them) , statistical mechanics implying thermodynamics, etc.)
Certainly probability and statistics were important in the development of these scinces, but they hadn't become crutches to try and get the status of being "scientific". There was a pursuit of truth by whatever means made most sense. Plain and simple.