Since the decline of Positivism, theoretical pluralism has become a widely held position. A survey of stratification views shows that many different conceptions exist, which can be organized in at least four frames of reference: (1) philosophy, (2) systems theory, (3) psychology, and (4) biology and motor theories. It is pointed out that stratification theories in frames 1–3 tend to be comprehensive but non-specific, whereas the opposite holds for theories in frame 4. In view of this, this paper addresses how a stratification theory for psychology may be constructed that is both comprehensive and specific. Firstly, it is argued that the low-to-high scale that generally characterizes stratification theories may be understood in terms of levels of activity. Secondly, it is argued that level of activity may be construed as the degree of coupling between (human) organism and environment with relatively high activity levels being characterized by a relatively low degree or "looseness' of coupling. Thus a conception is proposed of stratification as a scale of tight-to-loose organism-environment couplings.