"Between-person methods provide limited insight about within-person belief systems": Correction to Brandt and Morgan (2022).

Reports an error in "Between-person methods provide limited insight about within-person belief systems" by Mark J. Brandt and G. Scott Morgan (, 2022[Sep], Vol 123[3], 621-635). In the article (https://doi.org/10.1037/pspp0000404), the third sentence in the second paragraph of the Participants and Procedure section should appear instead as follows: Over this period, participants complete two surveys per month (12 waves in total). Each survey is open for approximately 2 weeks. Participants can complete the survey at any point during the 2 week period. The online version of this article has been corrected. (The following abstract of the original article appeared in record 2022-19898-001.) Belief systems are individual-level phenomena that describe the interrelationships of the political attitudes of a person. However, the modal study of the structure of political ideologies and beliefs uses cross-sectional survey data to estimate what is central to the belief system or the dimensionality of the belief system, aggregating across many people. Cross-sectional data, however, are ill-suited to the task of studying individual-level phenomena because they contain an unobservable mixture of within-person and between-person variation. In this project, we use longitudinal datasets from the Netherlands (representative) and the United States (convenience), spanning between 6 months and 10 years, to we ask whether between-subjects methods can help us understand the within-person structure of belief systems. First, we use Bayesian STARTS models (Lüdtke et al., 2018) to assess what type of variance cross-sectional studies are likely tapping into. We find that variability in measures of ideology and political beliefs is primarily due to stable between-person differences, with relatively smaller amounts of variation due to within-person differences. Second, we estimate between-person, within-person, and cross-sectional correlations between all items in our study and find that between-person correlations are larger and in some cases differ in their direction from within-person correlations. Furthermore, cross-sectional correlations are most similar to between-person correlations. Taken together, these findings indicate that the modal study may help describe differences between people, but is ill-suited to tell us about the structure of individuals' belief systems. New methods are necessary for a complete understanding of political belief systems that clarify both between- and within-person processes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).