 Because social kinds are distinctly anthropocentric, some theorists claim that the only plausible view we can hold is some form of constructivism about them. Hacking (1995, 1999) argues that in social contexts the object of classification itself changes in being classified. The fact that the people being classified are conscious makes for dynamic interactions between the classification and the classified. The latter may resist or embrace certain classifications (‘child abuser’, ‘hip’) and modify their behaviour accordingly. This leads to an change in the extensions of the relevant kind concepts. Furthermore, as the extensions change, the criteria for membership may change also. Many of our classifications in social science are evaluative. A social situation looks deviant from the norm and people make an evaluative judgment about this. Sometimes this means that people passively accept what experts say about them, and see themselves in that light. But feedback can direct itself in many ways. Alternatively, some people seek to reclassify themselves. Thus, classification in social science is interactive. Hacking argues that this is in marked contrast to the indifferent kinds that are found in natural science. An electron is indifferent to being classified as an electron.