Assessing trait negative affect with the Spielberger State-Trait Inventory over 3.5 years: Evidence of satisfactorily short- but limited long-term stability

The Spielberger State Trait Anxiety Inventory (STAI) is the most cited measure of general trait negative affect and employed in a wide variety of research contexts. Although the STAI trait scale (STAI-T) is assumed to assess a trait-like characteristic, little is known about its long-term temporal stability. Here, we investigate the temporal stability of the German version STAI-T scale across multiple measurement time points spanning 5 months to 3.5 years in two independent samples (105 female Caucasians and 120 mixed sex Caucasians). We replicate previously reported high stability for intervals < 12 months, but decreasing stability with increasing time intervals. In addition, our data suggest that the STAI-T primarily measures general negative affect rather than anxiety specifically (despite its name) as indicated by the results of a nomological network analysis. Comparing temporal stability of the STAI-T in our work to temporal stabilities of these related constructs reported in the literature, we observed similar moderate temporal stability over longer time intervals for the STAI-T (32 months: r = .562; 41 months: r = .419). These results relate to the debate to what extent trait constructs are expected to be stable across longer time intervals and are of relevance for researchers aiming to use the STAI-T scale in longitudinal investigations or for long-term prediction.