Defaults (i.e., options that become effective without an active choice) have been found to be powerful tools to influence decision‐making in a range of behavioral domains. However, seemingly conflicting assumptions have been expressed regarding the interplay of defaults with individual attitudes. Whereas some expect attitude‐conditional effects (i.e., a statistical default‐by‐attitude interaction), others assume an attitude‐unconditional effectiveness of defaults (i.e., statistically additive effects). Integrating both assumptions, we argue that the interplay of defaults and attitudes depends on what is considered a default effect. Specifically, whereas default acceptance is likely to be attitude‐conditional, we predicted that defaults and attitudes would add up in explaining people's actual choices. We tested these hypotheses in an online shopping scenario presenting environmentally friendly or conventional default products to 231 participants. Participants’ environmental attitude was assessed with the General Ecological Behavior scale and actual product choices were identified if participants rejected a given default product. In line with our hypotheses, default acceptance was predicted by a default‐by‐attitude interaction. In contrast, actual environmentally friendly product choices were found to be an additive function of defaults and participants’ environmental attitude. From an applied perspective, our findings suggest that defaults can readily be applied even in attitude‐heterogeneous target populations. Concurrently, however, our findings also speak of the importance of people's attitudes for understanding individual decision‐making.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.