Diffusion is the opposite of focussing; it is a concomitant of the breakdown of family ties or religious beliefs, a redistribution of economic or political or defence interests, of the decay of mutual intelligibility, or physical dispersion, of disparate upbringing. A culture, or a language, may be focussed at one level of use and diffuse at another; at other periods it may be equally focussed or diffused at all levels.
- Le Page (1977), Pag. 239-240