Usually people refer to sciences like Physics as "hard" because you can precisely control variables leading to precise equations. Psychology is "soft" because there are so many mechanisms behind any single behavior we can't control them all. Psychology has control groups, random assignment, and results with scattering dots rather than equations. I feel this is overly simplistic, since Physics has examples where you can't control every variable (e.g., Quantum Mechanics, Thermodynamics) and Psychology has examples where you can control nearly everything - resulting in precise equations (e.g., Ebbinghaus' Forgetting Curve). If you wanted, you could probably sensibly distinguish the phenomena in Psychology where we are able to experimental control more and have more precise equations in our results from phenomena in Psychology where we lack experimental control. I worry you would be implicitly conveying a value judgement where "hard" is more real and worthwhile than "soft." But really "hard" and "soft" is more about the phenomena being studied than science itself. Everything "hard" and "soft" is worth our best efforts to understand through the scientific method. Best wishes with your thinking, Chetan. ~ Kevin

In psychology if soft is weak and hard is strong and we know that our weakest point can be our strongest asset, it would not make sense to introduce that dichotomy because it would be misleading.

Thank you Kevin and Beatrice for this note!