Plastic is creating serious environmental concerns. Social norms can help reduce unsustainable behavior, especially when the referent is socially close to the individual. The present study aimed to examine the effect of referent specificity in dynamic norms on intention to reduce plastic use and the role of collective pride as a mediator in this relationship. Social identification was also tested for its moderating effect on the relationship between referent specificity and intention. Participants were randomly exposed to dynamic norms with a specific referent (college students, n =57), general referent (Portuguese, n = 49) or no norm exposure (control group, n = 64) and answered a questionnaire about collective pride and pro-environmental intention. We hypothesized participants in the specific condition would have higher intention compared to the general and control conditions (H1), that this effect would be stronger for high identifiers with the referent (H2), and that collective pride would mediate the link between referent specificity and intention (H3). Results showed the specific referent did not differ from the general referent or the control condition regarding intention to reduce plastic. Intention in the general referent was significantly lower from the control condition. Social identification moderates the impact of dynamic norms on intention - those who identify less with the general referent have higher intention to reduce plastic than those with higher identification. Collective pride was higher in the specific condition compared with the general but did not mediate the relationship between norm and intention. Findings and practical implications will be discussed.