Ummm, cause it's not really a science?

Measuring Progress: Why Is Social Science Not as Successful as Natural Science?

Social "science" are really the old liberal arts...

liberal (adj.)

mid-14c., "generous," also, late 14c., "selfless; noble, nobly born; abundant," and, early 15c., in a bad sense "extravagant, unrestrained," from Old French liberal "befitting free men, noble, generous, willing, zealous" (12c.), from Latin liberalis "noble, gracious, munificent, generous," literally "of freedom, pertaining to or befitting a free man," from liber "free, unrestricted, unimpeded; unbridled, unchecked, licentious," from PIE *leudh-ero-, probably originally "belonging to the people" (though the precise semantic development is obscure; compare frank (adj.)), and a suffixed form of the base *leudh- "people" (cognates: Old Church Slavonic ljudu, Lithuanian liaudis, Old English leod, German Leute "nation, people;" Old High German liut "person, people").