Why do they call phsychiatrists, shrinks?

Why do they call phsychiatrists, shrinks?

Head-shrinker. He cures your swelled head.

Is there an origin for it, or someone who coined the phrase?

The OED lists it as American slang. Earliest cite is from Thomas Pynchon in 1966, but I doubt he coined it.

It was a reference to the variou headshrinker tribes.

Websters has a date of 1590 on that but it may be from another definition. They give this:
“3 [short for headshrinker] : a clinical psychiatrist or psychologist regaling us with all the stories he never told his shrink Rolling Stone

That is one weird sentence there.

Word Detective

The doctors at the psych hospital I worked at years ago called their staff-league softball team “The Jivaros”, after the South American tribe that’s best known for making shrunken heads. Somebody there wasn’t pompous about the profession!