Not invented here (NIH) is the philosophy of social, corporate, or institutional cultures that avoid using or buying already existing products, research, standards, or knowledge because of their external origins and costs. The reasons for not wanting to use the work of others are varied, but can include fear through lack of understanding, an unwillingness to value the work of others, or forming part of a wider “turf war”. As a social phenomenon, this philosophy manifests as an unwillingness to adopt an idea or product because it originates from another culture, a form of nationalism. The term is normally used in a pejorative sense. The opposite predisposition is sometimes called “proudly found elsewhere” (PFE) or invented here.