The psychology of nudging: An investigation of effectiveness and acceptability

This dissertation aimed to examine when and for whom nudges can be an effective and acceptable means of stimulating desired behavior. Since the introduction of the term ‘nudge’, the intervention has become increasingly popular both in scientific research and public policy. Nudges offer to be a novel and supplemental policy tool that goes with the grain of human behavior rather than combating all of its complexities. Scientific research thus far has established promising results regarding effectiveness and acceptability, but less is currently known about the conditions under which these nudges are effective and acceptable. The first part of the dissertation focused on the question when nudges are effective. We showed that nudges are equally effective under low and high cognitive load, suggesting that nudges do not take advantage of Type 1 processing, but rather that they are effective without the need for deliberation. Deliberation, if stimulated with instructions, has independent effects on choice outcomes next to the presence of an effective nudge. We further show that nudges can remain effective in more complex situations with more alternative options in the choice set. Next, we focused on the question for whom nudges are effective, and we showed that default nudges and autonomous motivation independently predict behaviors that people are at least moderately motivated for. Default nudges also have incremental value on top of existing motivation. Finally, we focused on the question for whom nudges are acceptable. Across a wide range of self-regulation variables, we showed that autonomous motivation is the only consistent predictor of nudge acceptability, while self-regulation capacity does not meaningfully affect ratings of acceptability. By focusing on these aspects, the current dissertation addressed core questions that surround many issues of the theory, practice, and ethics of nudging. As such, the dissertation aimed to contribute to building a robust science of nudging that is theoretically sound and more efficacious in its implementation.