Hearing impaired
The term offended his new acquaintance because deaf people do not regard themselves hearing impaired. it certainly arouse feelings of inadequacy when applied to them.
The answer to this question is <span>Folkway
</span><span>Folkway refers to an acceptable way of living that is held by a certain group of people. During the flight, it is considered unpolite to hog the armrests on either side because it will reduce the physical space that held by the people on your left&right. (they probably angry at john but decided not to confront)</span>