Where did the term Shrink for psychiatrist come from?

[dbhost]

I know dumb though, but my brain has been chewing on this one today... Any thoughts or should I go see a shrink?

[woodturner]

I know dumb though, but my brain has been chewing on this one today... Any thoughts or should I go see a shrink?

Good question, I assumed it was a reference to tribal practices of (literally) shrinking the heads of enemies. Wordorigin suggests that is the case:
http://www.wordorigins.org/index.php/shrink/
"It is based on a metaphor that evokes the image of a head-hunter who preserves shrunken heads. "

There seem to be a lot of ideas on the origin, though, and no general consensus. I have not been able to locate an authoritative source.