Sustainable consumption obtains ever-increasing importance due to
pressing social, environmental and economic issues. Extensive research
has proposed the use of social norm communication as an effective means
to encourage various kinds of pro-environmental behaviour, as well as
sustainable consumption. However, although crucial to the development of
effective social norm campaigns, tangible evidence for specific
processes and conditions through which social norms foster sustainable
consumption remains scarce. Thus, we aim to illuminate the underlying
mechanisms and boundary conditions of social normative influences and
clarify how to effectively communicate social norms. Study 1 examines
personal norms as a mediator of social normative influences on
consumers' purchase intention for an unsustainable product, including
the interacting role of personal traits (i.e., self-efficacy and
self-concept). The results reveal that personal norms fully mediate the
effect of perceived social norms on purchase intentions. For
participants expressing high generalized self-efficacy, an additional
direct effect of perceived social norms on purchase intentions arises.
The same pattern appears for a strong collective but not for a strong
relational self-concept. Study 2 investigates sender-specific (i.e.,
social distance) and recipient-specific (i.e., gender and
pro-sustainability world view) factors impacting the relative influence
of social normative message frames (i.e., injunctive vs. descriptive) on
purchase intentions towards a sustainable product. The results reveal
an interaction effect for social distance and for gender, but not for
pro-sustainability world view. This research proposes implications for
researchers, as well as marketers, and emphasizes auspicious aspects as a
springboard for future research.