Less is not always more: The case of the 36-item short form of the Zimbardo Time Perspective Inventory

Recently, a shortened version of the Zimbardo Time Perspective Inventory (ZPTI; Zimbardo & Boyd, 1999) was proposed as a “gold standard” (Sircova et al., 2014, p. 9). In this study, we examined the internal consistency and structural validity of this version of the ZPTI in samples of adolescents from the United Kingdom (N = 913) and the United States (N = 815), and adults from Australia (N = 667). Results provided support for the internal consistency of ZPTI scores, but structural validity analyses indicated poor fit and numerous problematic items. The findings call into question the use of scores on this shortened version of the ZTPI.