One of the fundamental shortcomings of the empirical psychological literature on mental disorders, personality aspects, intelligence, or emotions is that there is a lack of depth regarding the discussion what these psychological constructs are. Researchers often use statistical models such as factor models and find 3 depression factors or 5 personality factors, but it remains entirely unclear what these factors represent. I have written about this in more detail here regarding the psychopathology literature for which this challenge is especially severe.
I was asked recently by the Editor of Health Psychology Review to write a commentary on a paper by Peters & Crutzen entitled “Pragmatic Nihilism: How a Theory of Nothing can Help Health Psychology Progress” (URL). While the paper covers a few interesting ideas, it was somewhat consistent with the majority of the psychological literature in ignoring prior discussion on what psychological constructs are.
It made sense to summarize the ideas on the topic, and I responded with “What are psychological constructs? On the nature and statistical modeling of emotions, intelligence, personality traits and mental disorders” (URL). In the letter, I discuss four possibilities: psychological constructs are natural kinds (they are true things we discover), socially constructed kinds (they are categories we produce), pragmatic kinds (they should be useful), and complex kinds (they are emergent properties of complex systems):
Many scholars have raised two related questions: what are psychological constructs such as cognitions, emotions, attitudes, personality characteristics, and intelligence? And how are they best modeled statistically? This commentary provides (1) an overview of common theories and statistical models, (2) connects these two domains, and (3) discusses how the recently proposed framework pragmatic nihilism (Peters & Crutzen, 2017) fits in.
The statistical models that relate to these conceptualizations are reflective latent variable models, formative latent variable models, and network models, summarized in the Figure below:
Figure 1. Schematic visualization of three types of statistical models for psychological constructs (PC). Left: reflective model where the latent variable (thick border) “PC” is the common cause for the ten observed indicators 1-10 (thin borders). Center: formative model where the latent variable is constructed from the indicators. Right: network model where the co-occurrence of all observed items is due to causal processes; there is no latent variable, and self-loops indicate that items cause each other over time.
Both the paper by Peters & Crutzen, and my commentary, were discussed by the clinical psychology blog Mad in America, and I hope they will spark other interesting debates.
Fried, E. I. (2017). What are psychological constructs? On the nature and statistical modeling of emotions, intelligence, personality traits and mental disorders. Health Psychology Review. http://doi.org/10.1080/17437199.2017.1306718 (URL).
Peters, G. Y., & Crutzen, R. (2017). Pragmatic Nihilism: How a Theory of Nothing can Help Health Psychology Progress. Health Psychology Review. http://doi.org/10.1080/17437199.2017.1284015 (URL).