Meaning, . . .duh
The Oxford English Dictionary Online (OED) defines "duh" as"
The use of "duh" as an expression of incomprehension describes the origins of the contemporary word. However, the "mildly derrogatory" use of the "duh" to point out another person's foolishness is the common usage today.
The fourth edition of the American Heritage Dictionary of English defines "duh" as an interjection "Used to express disdain for something deemed stupid or obvious, especially a self-evident remark." One online Dictionary of Slang defines the morphemically related "no duh" as "a sarcastic response used when someone states the obvious."
The word "duh" is essentially sarcastic. Steven Pinker explains, "The point of sarcasm is that by making an assertion that is manifestly false or accompanied by ostentatiously mannered intonation, one deliberately implies its opposite."1 In the case of "duh," the ostentatiously prolonged vowel sound and falling tone cue the meaning and distinguish it from the original word expressing incomprehension. The person who sarcastically says "duh" is, in fact, saying that incomprehension is manifestly unjustified.
"Doh!", on the other hand, does not have the implication of sarcasm. The Oxford English Dictionary Online defines "doh" as:
I disagree with the OED about the variant included in the definition. Interviewing young people from a broad range of schools, scanning the World Wide Web and watching many Simpson television re-runs, I find "Doh!" is always used to refer to a person's own frustration or stupidity, in accordance with the primary definition given by the OED.
There may be some confusion since "Doh!" appears to be derived from "duh". Both words became coin of the cultural realm during the last decades. Both articulate responses to foolishness. However, they have only recently become linked.
The American Heritage Dictionary describes the etymology of "duh" as "Imitative of the utterance attributed to slow-witted people." "Duh" evolved from the filler word "duh" (similar to "umm" or "uhh" in English) used to fill a pause while groping for appropriate words.
"Doh!", on the other hand, originated as a written device to express a grunt. The OED cites a 1953 book as its earliest written instance: "'Doh!' An anguished gasp of exasperation rang out loud and clear as Mr. Wilkins found his voice again."
In an interview with the creator of Homer Simpson, Matt Groening says that "Doh!" was originally written into the script as "Annoyed Grunt." Groening explains that "Doh!" is taken from an old character actor named James Finlayson, who was famous for his exaggerated double-takes in Laurel and Hardy films.
There is a fine difference between the sound made to fill space while thinking and a grunt meant to express annoyance or exasperation. "Duh" and "Doh!" do not have the same origins.
The antecedents of our contempoary "duh" and "Doh!" may have come from different parts of our brain, showing how very distinct the two words are.
Since it is a part of our language processes, I speculate that "duh" is produced in our left brain language centers. These areas detect sound sequences, produce oral-facial movement sequences and signing gestures. The left brain is where we find the tissue involved with short-term verbal memory and crucial areas that affect grammar, reading and naming.2 To me it makes sense that the "umm"s, "uhh"s, and "duh"s that fill in space while processing language come from these areas. (However, I am not sure and would appreciate hearing from anyone who can verify or correct this speculation.)
Annoyed grunts, in contrast, come from an entirely different part of the brain. Steven Pinker explains, "Human vocalizations other than language, like sobbing, laughing, moaning, and shouting in pain, are also controlled subcortically."3 When people swear, the articulation is not generated from our language center in the left side of the brain, but from the Supplementary Motor Cortex in the center of the brain.
The neurobiologist William Calvin points out that monkey vocalizations (barks, chatterings and cries) also come from this area in the center of the brain. "So it looks as if swearing in humans is analogous to the monkey's vocalizations--and indeed they are both rather emotional kinds of utterances. People who say swearing is rather primitive and unsophisticated may be more correct than they know,"4 Calvin writes.
With different brain areas responsible for the original pauses in language that gave rise to "duh" and the annoyed grunts that evolved into "Doh!", it seems clear that they are significantly different. Perhaps because Homer Simpson was both annoyed and imitating the sarcasm of "duh", the two words became linked. "Doh!" appears to be what Victoria Fromkin and Robert Rodman describe as a back-formation, in this case a deliberately incorrect morphological analysis by Homer Simpson to parody and deflate the sarcasm of "duh".
1. Steven Pinker, The Language Instinct, (first edition) p. 377. Note that web link is to more recent, paperback edition, while my quotations are from the hardback first edition.
2. Pinker, p. 334
3. Scientific American, June 2001, includes an article about "Sign Language in the Brain." Work with deaf people suffering aphasia shows that the left side of the brain is dominant for sign language, even as it is for speech.
4. William H. Calvin, The River That Flows Uphill: A Journey from the Big Bang to the Big Brain, p. 350.