How norms work: Self-identification, attitude and self-efficacy mediate the relation between descriptive social norms and vegetable intake.

Background: The current studies aim to show that descriptive social norms
influence vegetable intake and to investigate three potentially underlying processes
(self-identification, attitude, and self-efficacy). Methods: In two studies,
descriptive social norms regarding vegetable intake were manipulated (majority
vs. minority norm). Study 1 investigated both the relation between baseline
vegetable intake and self-identification, attitude, and self-efficacy, as well as the
effect of the norm manipulation on vegetable intake over a one-week period.
Study 2 investigated potential mediation of the effect of the manipulation on
vegetable intake intentions through self-identification, attitude, and selfefficacy.
Results: Study 1 showed that the proposed mediators were related to a
baseline measure of vegetable intake. Moreover, in participants identifying
strongly with the norm referent group, majority norms led to higher vegetable
consumption than minority norms. Study 2 showed that the direct effect of the
social norm manipulation on vegetable intake intentions was partly mediated by self-identification, attitude, and self-efficacy. Conclusions: These studies shed
first light on processes underlying the effect of descriptive social norms on
health behavior. A norm describing the behavior of a salient social group leads
people to identify more with, have more positive attitudes toward, and feel
more self-efficacious regarding that behavior.