Tuesday, October 8, 2013

Mitt Romney's false Depictive Sincerity Implicature


In a debate with Obama last year, Mitt Romney said, “Right now, the [Congressional Budget Office] says up to 20 million people will lose their insurance as Obamacare goes into effect next year.”



As PolitiFact pointed out, in fact, the Congressional Budget Office had calculated 5 different estimates:

  • an increase of 3 million
  • a decrease of 5 million (baseline)
  • a decrease of 10 million
  • a decrease of 12 million
  • a decrease of 20 million

The "baseline" or "most likely" estimate was the 5 million people would go off the insurance that they currently had (which I would not describe as "losing", but that's beside the point at the moment).

This connects to some of the research that I have done on scalar terms, starting with exclusives like only, merely, exclusively, sole, mere, and exclusive (official link here; PDF here), and then moving to the superlative modifiers at least and at most (here is our more theoretical paper and here is an experimental paper we did -- this is the one that has most to do with the Mitt Romney quote).  At most has been argued to be quite similar to Mitt Romney's up to, although this has been challenged. I will take at most and up to to be interchangeable for the purpose of the present discussion.


Let me back up a little bit. You might think that the following two sentences are equivalent, i.e. true under exactly the same circumstances:

Liz had more than 3 beers  <-->  Liz had at least 3 beers
Similarly, you might think that the following two sentences are equivalent:
Liz had fewer than 3 beers <--> Liz had at most 3 beers
But there are subtle differences between comparative modifiers like "more than" and "less than" and superlative modifiers like "at least" and "at most". One group of researchers did an experiment in which they gave participants a two sentence argument, where the first sentence was supposed to be the premise and the second sentence was supposed to be the conclusion, and they asked their participants to judge whether it was a good argument.  100% of their participants judged the following to be a good argument:
Liz had 3 beers. Therefore, Liz had more than 2 beers. (100%)
But only 50% of their participants judged the following sentence to be a good argument:
Liz had 3 beers. Therefore, Liz had at least 3 beers. (50%)
The comparative modifier "fewer than" behaved pretty much like its cousin "more than"; 93% judged the following to be valid:
Liz had 3 beers. Therefore, Liz had fewer than 4 beers. (93%)
But they had trouble with the superlative modifier "at most"; 61% judged the following to be a valid argument:
Liz had 3 beers. Therefore, Liz had at most 3 beers.
Why this difference? Researchers all seem to agree that superlative modifiers ("at least", "at most") imply that the speaker does not know how many objects of the relevant kind there are, while comparative modifiers do not have this implication. But there are two different schools of thought as to where this ignorance implication comes from:

  • According to some researchers, ignorance is an entailment, and the sentence is FALSE if the speaker knows how many objects of the relevant kind there are.
  • According to other researchers (myself included), ignorance is a conversational implicature, so the sentence may be ODD when the speaker knows how many objects of the relevant kind there are, but it's not necessarily FALSE.
My collaborator Thomas Brochhagen (University of Düsseldorf) and I did an experiment in order to find out what would happen when people are looking at a picture, of, say, 4 bananas, and it's clear to everyone how many bananas there are. Would they say that the sentence "There are at least 4 bananas in the picture" is FALSE? Here's an example stimulus from the experiment:



There are at least 4 bananas in the picture.
[ ] True
[ ] False

We found pretty much what I expected: If there are 4 bananas in the picture, then "There are at least 4 bananas in the picture" is reliably judged true (100% of the time). Same for "at most 4", "more than 3", "fewer than 5", and "at least 3".

But there was a twist.

Looking at a picture of 4 bananas, people were very likely to say that "There are at most 5 bananas in the picture" was FALSE.

Think about that. Looking at that picture with 4 bananas, would you say it is true or false that there are at most 5 bananas in it? 


There are at most 5 bananas in the picture.
[ ] True
[ ] False

A little less than half of our participants said it was true (44%), and a little more than half said false.

Well, this was surprising. None of the existing theories could explain that. We came up with an explanation along the following lines:
  • The sentence "There are at most 5 bananas in the picture" HIGHLIGHTS the possibility that there are 5 bananas in the picture.
  • The highlighted possibility is false.
  • There is a norm of conversation -- one of Grice's maxims -- which says that one shouldn't highlight possibilities that one knows to be false (or considers highly unlikely, as in Mitt Romney's case). We donned this norm the "Maxim of Depictive Sincerity".
So what Mitt Romney did was to highlight a false possibility. In other words, the "channel" through which Mitt Romney communicated a falsehood was what we can refer to as a Depictive Sincerity Implicature.

So we should add a notch on the Truth-O-Meter for depictive sincerity implicatures.