Environmental psychology can mean one of two related things:
1) An interdisciplinary field focused on the interplay between humans and their surroundings. By various researchers, this has also been termed environmental social sciences, architectural psychology, socio-architecture, ecological psychology, ecopsychology, behavioral geography, environment-behavior studies, person-environment studies, environmental sociology, social ecology, and environmental design research.
The second definition is essential for planning any campaign or other action to promote sustainability.
A study/case study found that a sign encouraging recycling had a dramatically different effect depending on the wording. "Please recycle" of had a modest effect - some people recycled, but many didn't. "We recycle" resulted in a much greater proportion of recycling.[verification needed]
- The first is Wikipedia's definition, but I believe it's used in the other sense too. --Chriswaterguy.