Motivated by default—How nudges facilitate people to act in line with their motivation.

Nudges are defined as small adjustments in the choice architecture that help people perform desirable behavior.How nudges interact with individuals' motivation has not been studied empirically.We conducted three studies with different types of defaults in three different behavioral domains and investigated how defaults and different types of motivation affect choice outcomes.In Study 1, we investigated the effectiveness of a default to stimulate healthy eating choices implemented in a hypothetical online supermarket setting.In Study 2, we used a scenario in which participants could choose from a list of green amenities (either preselected or not).In Study 3, we asked participants whether they wanted to participate in a basic or longer version of our questionnaire, with the longer version option set as the default in the nudge condition.Across these three studies we show that defaults are effective in promoting desirable behavior and that goal strivings and autonomous motivation have additional positive main effects.We did not find evidence that controlled motivation affected behavioral outcomes.Exploratory analyses revealed that amotivation negatively affected behavior, but the measure had poor reliability.No significant interaction effects were observed.Together, these studies imply that both defaults and motivation have main effects on behavior, such that the default sets the anchor from which people can adjust according to the type and strength of their motivation.Implications for the practice and ethics of nudging are discussed.