Chapter 1 - Universiteit Twente

General Introduction
resource. As a consequence, and similar to muscle failure after straining, a series of
self-regulatory acts will deplete people’s self-regulatory energy to the point of selfregulatory
failure (Baumeister, Schmeichel, & Vohs, 2007). In this state of self-regulatory
resource depletion (or ‘ego depletion’), the controlled, purposeful self fails to function
effectively, which renders people vulnerable to untoward impulses, habit, routine, and
automatic processes (Baumeister & Vohs, 2007; Vohs, Baumeister, & Ciarocco, 2005), all
key indicators of mindlessness.
In line with the statements of the limited-resource model of self-control, in this
dissertation the terms ‘self-regulation’ and ‘self-control’ will be used interchangeably.
Furthermore, whereas the ability to perform self-control is for an important part
determined by situational demands, it is dependent on individual differences as well
(Tangney, Baumeister, & Boone, 2004). Although individual differences in dispositional
self-control ability were also considered (Chapter 3, Experiment 3.4), this dissertation
mainly focuses on situational differences in self-control.
Many studies have shown that performing a (brief) preliminary act of self-control
undermines self-regulation on a subsequent, unrelated task. In a classic study by
Baumeister et al. (1998), participants were seated at a table with a stack of chocolate
chip cookies and a bowl of radishes placed in front of them. Ostensibly to study taste
perception, half the participants were to taste the cookies, but leave the radishes, and
the other half of participants were to taste the radishes, but was not allowed to eat
the cookies. Participants who had to force themselves to eat the radishes instead of
the tempting chocolate cookies subsequently quit faster on unsolvable figure tracing
puzzles than participants who did not have to exert self-control over eating. In a
comparable study by Muraven et al. (1998), participants were told to write down all
their thoughts. They were either instructed to think about a white bear as much as
they could, instructed not to think about a white bear, or they were given no special
thought control instructions. Participants who had to suppress thoughts about a white
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