Disciplinary differences in the development of scientific generalizations and explanations are reviewed in this article. The social and behavioral sciences have identified fewer laws, established fewer "paradigms," and developed "worse" theories than the physical sciences. We argue that the variability in the theoretical attainments of disciplines is due primarily to differences in the complexity of the topics studied. Accounts suggesting that differences in the maturity of disciplines are responsible for the variability are dismissed. In the study of complex phenomena, there is an extreme trade-off between generality and precision in which basic theories do not make the precise predictions needed for the development of applications and in which applied models are lacking in generality. The examination of proximal determinants and the generation of context-specific mathematical models are essential for prediction and application in complex disciplines. The impossibility of developing exacting theories of complex phenomena suggests that we need to redefine our conceptions of "good" and "bad" theories and "real" and "fake" science.
Keywords: complexity; social and behavioral sciences; theory development.