Middle-class, or Middle class?

[Chapman]

Hello! I'm not sure whether to put a hyphen between "middle" and "class" when referring to it as an adjective, ie. "middle-class Mexicans" as opposed to "the middle class" whereby I wouldn't put in a hyphen.

I've been taught that when used as an adjective, a compound noun should be joined by a hyphen, such as "gap-toothed smile". But the text I'm editing uses "middle class" indistinctly as a noun and an adjective, eg. The middle class Mexicans began arriving in XX country by 1940 and The middle class are the largest group.

I'd like it if someone could back me up (hehe) so I can justify adding a hyphen every time it's used as an adjective, or otherwise tell me it's fine keeping the two words separate. Thanks for your suggestions!

 

[Egmont]

Use a hyphen. The hyphen alerts the reader that a word should be read together with the following word. That avoids the problem of someone reading middle, continuing with class, forming a mental idea of what the sentence is about, and then having to discard this idea on encountering Mexicans. This process is subconscious, it takes place in a fraction of a second, but it takes mental energy away from understanding the message that the writer is trying to convey.

 

[Rover_KE]

The WR dictionary hyphenates the adjectival form 'middle-class', but leaves the adjective and noun form unhyphenated.

 

[Chapman]

Thank you to you both - very helpful!