A key assumption in the person-oriented approach is that a person must be understood as a complex, integrated system, represented by patterns of within-person variation rather than scores on separate variables. The term ‘system’ does, however, have multiple meanings, which are not clearly distinguished in the person-oriented literature. I try to disentangle causal interactionism, which describes the psychological consequences and functions of each component of the system as dependent upon its causal interaction with other system components, from content holism, which (...) describes the system components as in part constituted by their relations to each other and the system as a whole. Although the terms ‘interactionism’ and ‘holism’ are often treated as combinable and interchangeable, causal interactionism and content holism pertain to distinct kinds of research problems. Causal interactionism construes the person in terms of the hierarchically structured mechanistic systems that underpin his or her attributes and shape them over time, and can be exemplified in terms of Magnusson’s developmental approach, whereas content holism is integral to our understanding of the person as an intentional system, whose mental states and actions are interweaved through principles or logic and rationality rather than material causality, and can be exemplified in terms of Stephenson’s Q-methodological approach. (shrink)

We can often explain a person's action by citing some fact which prompted him to do what he did. For example:Tom quit his job because he was offered more money elsewhere;Dick took his daughter to the dentist because she had a toothache;Harry rushed out of the theater because it was on fire.In each case there are four elements which fit together in a characteristic pattern. The first is the fact that Tom has been offered more money, that Dick's daughter has (...) a toothache, or that the theater in which Harry is sitting is on fire. If the theater were not on fire, for example, then we would have to give a different sort of explanation of why Harry rushed out: we would have to say that he left because he thought it was on fire, not because it was on fire. I shall have more to say about this point later. The second is their knowledge of these facts. If Dick is unaware of the girl's toothache, he can hardly do anything on account of it; and of course the same goes for the other cases. The third element is the attitude which each agent has toward the existing state-of-affairs. Tom wants to earn more money; Dick loves his daughter and doesn't want her to suffer; and Harry, like the rest of us, doesn't want to be burned. Finally, there is the action which is being explained: Tom quits his job, Dick takes the girl to the dentist, and Harry rushes from the theater. (shrink)