ABSTRACT
According to the National Institute for Occupational Safety and Health, occupational health psychology (OHP) involves “the application of psychology to improving the quality of work life, and to protecting and promoting the safety, health and well-being of workers” (NIOSH, 2013). Although not everyone may agree with this definition (is OHPresearch only about the application of currently available psychological knowledge to working life, or does it also generate new and even fundamental insights?), to make a difference in workers’ lives is certainly a key concern in our discipline. Achieving this aim requires in-depth knowledge of the causal processes that affect these desiderata: healthy work and healthy workers. In order to obtain such knowledge, we need longitudinal studies in which the same variables are measured at least twice across time for the same set of participants (e.g. Hassett & Paavilainen-Mäntymäki, 2013; Menard, 2007; Ployhart & Vandenberg, 2010). Although cross-sectional designs can tell us whether particular variables are associated in ways that are proposed by theories, longitudinal research designs can also provide us with information about the temporal order of the events underlying these associations, show how the presumed “outcomes” have changed across time and whether this change can be ascribed to (changes in) the alleged “independent” variables. Accordingly, over the last two decades the number of OHP studies examining causal processes through longitudinal research designs has increased steadily (see, for instance, Austin, Scherbaum, & Mahlmann, 2002; StoneRomero, 2011). A number of such studies are included in this special edition of Work & Stress, which is devoted to longitudinal research.
