One of my Rules for Social Science Research is “Don’t Use Metaphors”. Natural scientists don’t use metaphors. Physicists, chemists, et al. don’t tell us what something is like but, rather, what it is. Social scientists should do likewise; should demonstrate what is.
The reason social scientists should follow the practice in natural science and not use metaphors is that, invariably, a metaphor is different than the phenomenon it’s supposed to depict or describe. An example concerning an important topic–using the Internet and online tools to more effectively deal with problems–is provided in a book I’m reading for one of my writing projects (Internet Citizens: Anyone, Anywhere, Anytime), Reinventing Discovery: The New Era of Networked Science:
“[It’s] . . . common . . . to suggest that online tools enable some sort of collective brain, with the people in the group playing the role of neurons. A greater intelligence then somehow emerges from the connections between these human neurons. While this metaphor is stimulating, it has many problems. The brain’s origin and hardware are completely different from those of the Internet, and there’s no compelling reason to suppose the brain is an accurate model of how collective intelligence works, or how it can best be amplified. Whatever our collective brain is doing, it seems likely to work according to very different principles than the brain inside our heads. Furthermore, we don’t yet have a good understanding of how the human brain works, so the metaphor is in any case of limited use at best” (pp. 18-19).