The Environmental Identity (EID) Scale can be used to measure a person’s environmental identity, or their sense of connection to the natural world. It can be helpful to assess a person’s environmental identity because this identity can have a broad and lasting influence on their behavior. The scale measures different aspects of a person’s environmental identity, including 1) self-identification (based on the extent and importance of an individual’s interaction with nature), 2) ideology (based on support for environmentally friendly lifestyle choices), and 3) positive emotions toward the environment (based on enjoyment obtained in nature).