Abstract
In recent years, more and more authors have called attention to the fact that the theoretical foundations of psychology are shaky. This has led to a lively debate on the “theory crisis” in psychology, which is argued to be more fundamental than the replication crisis that has received much more attention. In this talk, I first consider why there are so few good theories in psychology, and why psychology differs in this respect from other fields, and then argue that the lack of good psychological theories also creates fundamental challenges to psychological measurement. First, there has been insufficient attention on the conceptual clarity of psychological constructs. The same construct is often operationalized in wildly divergent ways in different fields, or different constructs are created for the same underlying phenomenon. For example, there are over 30 different constructs related to “perceived control”. The result is that psychology is permeated with numerous constructs and concepts of insufficient clarity, which is a problem for theory construction, as concepts are the building blocks of theories. Moreover, this lack of conceptual clarity is also closely linked to problems of psychological measurement: It is hard to provide valid measurements of constructs that are not well defined, as the discussion on the measurement of happiness and well-being illustrates. Strikingly, most studies in psychology report little or no validity evidence whatsoever for the constructs used. Second, psychological states are difficult to directly intervene on, and effects of interventions are hard to reliably track, which poses great challenges for establishing psychological causes or mechanisms. More specifically, interventions on psychological variables such as affects states or symptoms are not “surgical” but “fat-handed” in the sense that they change several variables at once. This makes it extremely difficult to infer causal relationships between psychological variables, and insofar as theories should track causal relationships, this hinders the development of good psychological theories. In addition, it is widely thought that valid measurement requires establishing a causal relationship between the attribute that is measured (e.g., temperature) and the measurement outcome (e.g., thermometer readings). Insofar as this is the case, the problem of psychological interventions is also directly a problem for psychological measurement. In light of these issues, it is understandable that psychological theories tend to come and go, without much cumulative progress, and that the very possibility of psychological measurement continues to be debated. However, I will end the talk on a positive note, considering some ways of making progress in psychology: Focusing more on conceptual clarification instead of just statistics and experiments; and embracing a holistic and pragmatic approach, where measurement, theorizing, and conceptual clarification are seen as necessary parts of an ongoing iterative cycle.
