Follow the signal: When past pro-environmental actions signal who you are

Research has shown that past pro-environmental actions can promote as well as inhibit subsequent environmentally-friendly behaviour. When are past pro-environmental actions likely to lead to more environmentally-friendly behaviour? We propose this depends on the extent to which initial actions are linked to people's environmental self-identity. We hypothesise that past pro-environmental actions are more likely to influence one's environmental self-identity when the behaviour implies something about you. As expected, environmental self-identity was stronger when the initial behaviour more strongly signals that you are a pro-environmental person. The signalling strength of previous pro-environmental actions was high when people considered a wide range of past pro-environmental actions, or when the initial behaviour was difficult and unique. Our results suggest that pro-environmental behaviour can be promoted by reminding people of their past pro-environmental actions, particularly when these actions strongly signal that one is a pro-environmental person, thereby strengthening environmental self-identity.