Why are the social sciences so bad at predicting and explaining phenomena? I often hear three answers to this question, and none of them are satisfactory.
First, there is the appeal to novelty. Social science, we are told, is a relatively new field of study that is still in its

infancy when compared to the natural sciences. This is not a satisfactory explanation. Human interest in explanations of what governs social affairs is at least as old as human interest in explanations of what governs nature. And formally, social science has been around for at

least 150 years; the first 150 years of academic physics yielded the industrial revolution, the first 150 years of academic biology yielded evolutionary theory and the germ theory of disease, and the first 150 years of academic social sciences has yielded... zilch.
Next, there's

the appeal to complexity. Social systems, we are told, are so complex that they will invariably resist the kind of analyses typically found in natural explanations. This is also unsatisfactory, because it implies that there is a shortage of complexity in the natural world,

suggesting that nature is inherently tidy in its organization (which it isn't.)
Finally, there is the appeal to experimental limitations. Social sciences, we are told, are deeply restricted in the kinds of experiments that can be performed to see how social variables respond to

social influences. The implication here is that experimentation is the primary means by which regularities are discovered. This again is unsatisfactory, since paleontology, astronomy, and geology are almost completely devoid of experimental content, yet are perfectly serviceable

sciences. So the question remains: why do the social sciences suck so much? Why don't they predict and explain social phenomena like they're supposed to?