The same change can be made to each of the words below to make new ones. What is the change and what are the new words?

VISITOR
WHITEN
AGITATE
CELERITY
SUBTITLE
COMPSOSITE

HINT:
Unable to control one's emotions

Answers:

Dropping the letters IT from each word will leave a new word:

VISOR
WHEN
AGATE
CELERY
SUBTLE
COMPOSE 

Credit:
Will Shortz
The Puzzlemaster Presents Vol. 2
LOSING IT