Swedish Zimbardo Time Perspective Inventory (S-ZTPI)

S-ZTPI contains 64 items. Each item is a statement concerning view of/attitudes to time. The questionnaire differs from the original inventory of 56 items (Zimbardo and Boyd, 1999) in that it differentiates positive and negative aspects of the future TP, by adding eight new items to the inventory for the Future Negative scale (two original items for the unitary Future are in addition assigned to Future Negative, while the remaining items form a Future Positive scale). Confirmatory factor analyses provided support of the proposed six-factor structure and internal consistencies ranged from 0.65 to 0.94 across subscales (Carelli et al., 2011). The participants are requested to rate how characteristic each statement is of his/her own view, on five-point Likert scale from very uncharacteristic (coded as 1) to very characteristic (coded as 5). S-ZTPI items belong to one of six subscales: Past Negative (e.g., “Painful past experiences keep being replayed in my mind”), Past Positive (e.g., “Familiar childhood sights, sounds, smells often bring back a flood of wonderful memories”), Present Fatalistic (e.g., “Fate determines much in my life”), Present Hedonistic (e.g., “I believe that getting together with one's friends to party is one of life's important pleasure”), Future Negative (e.g., ”To think about my future makes me sad”) and Future Positive (e.g., “When I want to achieve something, I set goals and consider specific means for reaching those goals”). The subscale scores are computed as the average of rating (1–5) across items.

For the German participants we used the German 56-items version (Reuschenbach et al., 2013). Moreover, the Future Negative items were added to the German scale after being translated forward and backward.

To capture TP biases across all of the TP dimensions, we computed Deviation from a Balanced TP (DBTP; Stolarski et al., 2011). We used the revised version of the formula in Rönnlund et al. (2017) that takes the Future Positive vs. Negative distinction into account:

where o = optimal score and e = empirical (i.e., observed) score. In accord with several previous studies (Stolarski et al., 2011; Rönnlund et al., 2017), optimal scores were set to: oPN = 1.95, oPP = 4.6, oPF = 1.5, oPH = 3.9, oF/oFP = 4.0, and oFN = 1.8.

An alternative way to estimate DBTP was suggested recently by Jankowski et al. (2020). The arguments raised by Jankowski and colleagues is that the original formula in Stolarski et al. (2011) should be adjusted to include extreme points for three dimensions oPN (=1), oPP (=5), oF (= 5) and an optimal value for PH = 3.4. To examine the possibility that the revised formula would give a different result to those first reported, we recomputed DBTP (the revised formula did not include Future Negative, but, by analogy, oFN was set to (1) and re-run subsequent analyses involving DBTP). The results were highly similar to those presented (i.e., the same patterns of significant direct/indirect effects). We therefore report values based on the original formula for S-ZTPI in Rönnlund et al. (2017).