Humans on the other hand are unpredictable. So if you run an experiment that says X, it may or may not replicate later
humans can be studied and exhibit very predictable patterns.
Seems somewhat contradictory. If humans can be studied and exhibit predictable patterns, why wouldn't we expect experiments to be repeatable, as the parent comment asked?
And if the experiments are highly random, then either you should be conducting more of them over and over to get a valid statistical sample, or you shouldn't be conducting them at all. Either way I see no valid argument that studies in social sciences shouldn't be repeatable.