Sustaining a sustainable lifestyle: a longitudinal and experimental investigation of environmental identity and pro-environmental behaviors

Abstract

Harmful changes in the natural environment are occurring at an alarming rate, many of which are related to human behavior; individuals must start acting more sustainably (i.e., engaging in behaviors that help and do not harm the natural environment). The current study examined the role of environmental identity on behavior and whether one’s identity as an environmentalist changes over time. Participants were randomly assigned to complete a new behavior related to sustainability (sustainable condition) or a behavior related to a personal on-going goal pursuit (control condition). Participants completed a 3-week longitudinal study with four sessions, each 1 week apart, rating environmental identity (EI) and pro-environmental behaviors (PEBs; e.g., shopping using reusable bags, eating less meat) at each session. Results showed condition did not affect change in EI nor change in PEBs over time. However, condition did affect behavior at Session 4, choosing to learn about sustainability, such that individuals in the sustainable condition were more likely to choose to watch a 15-minute narrated PowerPoint about sustainability. Ignoring condition, EI decreased over the course of the study; PEBs did not change. Moderators of the effect of time on environmental identity were egoistic and biospheric values, connectedness to nature, ecocentric and anthropocentric attitudes, and political orientation. Although change in EI did not predict change in PEBs and vice versa, EI at Session 1 predicted PEBs at Session 2, PEBs at Session 2 predicted EI at Session 3, and EI at Session 3 predicted PEBs at Session 4 (each controlling for previous levels of EI and PEBs). Thus, evidence suggests EI and PEBs do influence one another but at different times.