“…The TTM is well suited to application to PI and the self-improvement hypothesis because it deals with sustained behavior change: change as a long-term process of preparation, change, and subsequent maintenance of new behavior(s). In addition, many of the concepts and ideas from the TTM are shared by a variety of other behavior (change) models, like the theory of planned behavior (Ajzen, 1985), the health belief model (Rosenstock, 1974), and various others (Bagozzi, 2000;Bandura, 1977Bandura, , 1991De Vries et al, 2003;Fishbein, 2000;Hagger & Chatzisarantis, 2014;Klein, Mogles, & Van Wissen, 2011;Kluger & DeNisi, 1998;Maes & Gebhardt, 2000;Rogers, 1975;Ryan, 2009;Schwarzer, 2008;Witte, 1992). For these reasons, we use the TTM as a starting point in our discussion of existing behavior change models and how they compare to the self-improvement hypothesis.…”