2026/08/01 by Jonathan L. Chia, Markus Wettstein, Andree Hartanto
paper · doi:10.1177/01650254261471350
crossref issued 2026/08/01 · crossref published 2026/08/01 · crossref published-online 2026/08/01 · crossref created 2026/08/01 · crossref deposited 2026/08/03 · crossref indexed 2026/08/03
Despite the use of latent growth mixture modelling (LGMM) to study longitudinal changes, existing practices may inadvertently impede this very investigation. Although subgroup trajectories may theoretically differ in their structure (e.g., some subgroups being linear, some curvilinear), the current convention advocates overreliance on the baseline model to derive subsequent profile trajectories, which may obscure these structural differences. In this article, we provide a brief description of extant LGMM practices, after which we explicate the pitfalls of the current approach. Finally, we provide a principled approach for LGMM research moving forward. Specifically, we recommend specifying a set of theoretically plausible models that differ in the number of growth factors and selecting the most expansive model that demonstrates acceptable fit to the data.