Kenneth G. Wilson (1923). The Columbia Guide to Standard American English. 1993.
CONSTITUENCY
The constituencies to which you belong (and everyone belongs to more than a few) help set limits and add variety to your usage. They include the members of your family, your closest friends, your colleagues at work, people who share your religious preference, your political interests and loyalties, your racial and ethnic roots, your age, and your sex, and all the other groups large and small to which you may belong. Your dedication to particular hobbies and fandoms links you to still other constituencies.
The constituencies to which you belong set the standards for your language practice within each. Obviously they overlap, but obviously too you are unconsciously skillful at saving the jargon of philately for your talking and writing to other stamp collectors and restricting the private diction and syntax of your Intimate level to use with those at home. Children, with their lack of experience, make frequent errors in adapting to new constituencies, and adults of limited experience also sometimes suffer when faced with new constituencies. Being able to adjust accurately and quickly to each new constituency and context you encounter is a mark of the mature, widely experienced person; this book tries to help you do so.