Etymology of adding articles to insulting or negative adjectives

I recently saw Deadpool (great movie), and noticed that Negasonic Teenage Warhead responded to something Deadpool said with "That a stupid."

But a few months before that movie was released, I heard some teenagers telling each other "You're a dumb!"

Where did this process of adding an article to dumb or stupid come from?

Solution 1:

I haven't thought of a way to isolate the singular noun usage, but 'crazies' became increasingly more widely used after 1964, according to this Google Ngram. I'd guess that nounal 'a crazy' would have the same growth in popularity.

I've chosen 'crazy' because it sticks in my mind as one of the first of these seldom-nouned adjectives I encountered.

However, as the Ngram shows, the nounal usage was around well before the 1960s. M-W records the first known usage as 1867, as compared with 1566 for the adjective.

Solution 2:

In spanish we use that syntax. "Eres un tonto," "You are a dumb," and examples in plural form such as, "Son unos tontos," "They are some dumbs". In english we perceive this expresion as wrong, but something odd tells us not to believe that entirely.