Many American speakers, myself included, have the impulse to laugh at statements like the following:
Mendendez and Ensign try to pressurize the White House
Should parents pressurize their children to get high marks in exams?
We laugh because we think that pressurize should apply only to things like airplane cabins and pressure cookers. Some people who object to the use of pressurize in the context of psychological pressure often become quite testy in their criticisms:
“I was pressurized into attending a girl’s college.” I don’t think she meant she had an air hose hooked up to an orifice to inflate her.
The idea is that pressurize should be reserved for technology, while pressure is the only acceptable verb to use when speaking of psychological pressure.
Neither British nor American dictionaries support the distinction. The online Oxford Dictionaries site offers the following among their examples of correct usage:
Don’t let anyone pressurize you into snap decisions.
People had been pressurized to vote.
The online Merriam-Webster dictionary gives this example:
Don’t let them pressurize you to do anything you don’t want to do.
The noun pressure has been in the language since the Middle Ages, but the verbs pressure and pressurize are fairly recent coinages. Both verb forms originated in North America.
The earliest OED citation for pressure with the meaning, “to apply pressure to, to coerce or persuade by applying psychological or moral pressure,” is from a Canadian publication dated 1911:
Extreme protection brought the formation of gigantic trusts, which pressured the consumers, who are now in open revolt against that regime.
The verb form pressurize was coined to describe the process of producing artificial atmospheric pressure. Pressurizing appears in 1940; pressurized in 1944. The use of pressurize to mean “to apply psychological pressure” is first documented in 1945:
Thus, selective service continues to ‘pressurize’ recalcitrant military unfits into war plants.
The use of quotation marks around pressurize indicates that the word was being used in a novel way.
The most that can be said about pressure vs pressurize is that American usage prefers to reserve pressurize for technical contexts and save pressure for psychological contexts. Speakers and writers of British English don’t seem to be aware of any such distinction:
A spokesperson of General Musharraf’s party said that fresh petition is an attempt to pressurize him to leave the country.
He [Pravin Togadia ]also said that this election is the best time to pressurize political parties to ensure safety of Hindus.
Brown’s administration “considered that any attempts to pressurize or lobby the Scottish government could be counterproductive to achieving this outcome
Bottom line: Americans can continue to laugh at the use of pressurize in a psychological context, but British speakers are not amused.