Why can you mumble “good morning” and still be understood?

I got an interesting question on Facebook a while ago and though it might be a good topic for a blog post:

I say “good morning” to nearly everyone I see while I’m out running. But I don’t actually say “good”, do I? It’s more like “g’ morning” or “uh morning”. Never just morning by itself, and never a fully articulated good. Is there a name for this grunt that replaces a word? Is this behavior common among English speakers, only southeastern speakers, or only pre-coffee speakers?

This sort of thing is actually very common in speech, especially in conversation. (Or “in the wild” as us laboratory types like to call it.) The fancy-pants name for it is “hypoarticulation”. That’s less (hypo) speech-producing movements of the mouth and throat (articulation). On the other end of the spectrum you have “hyperarticulation” where you very. carefully. produce. each. individual. sound.

Ok, so you can change how much effort you put into producing speech sounds, fair enough. But why? Why don’t we just sort of find a happy medium and hang out there? Two reasons:

1. Humans are fundamentally lazy. To clarify: articulation costs energy, and energy is a limited resource. More careful articulation also takes more time, which, again, is a limited resource. So the most efficient speech will be very fast and made with very small articulator movements. Reducing the word “good” to just “g” or “uh” is a great example of this type of reduction.
2. On the other hand, we do want to communicate clearly. As my advisor’s fond of saying, we need exactly enough pointers to get people to the same word we have in mind. So if you point behind someone and say “er!” and it could be either a tiger or a bear, that’s not very helpful. And we’re very aware of this in production: there’s evidence that we’re more likely to hyperarticulate words that are harder to understand.

So we want to communicate clearly and unambiguously, but with as little effort as possible. But how does that tie in with this example? “G” could be “great” or “grass” or “génial “, and “uh” could be any number of things. For this we need to look outside the linguistic system.

The thing is, language is a social activity and when we’re using language we’re almost always doing so with other people. And whenever we interact with other people, we’re always trying to guess what they know. If we’re pretty sure someone can get to the word we mean with less information, for example if we’ve already said it once in the conversation, then we will expend less effort in producing the word. These contexts where things are really easily guessable are called “low entropy“. And in a social context like jogging past someone in the morning, phrases liked “good morning” have very low entropy. Much lower than, for example “Could you hand me that pickle?”–if you jogged past someone  and said that you’d be very likely to hyperarticulate to make sure they understood.