The Three Hardest Words in the English Language (Ep. 167)

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(Photo: mrpolyonymous)

(Photo: mrpolyonymous)

This week’s episode is called “The Three Hardest Words in the English Language.” (You can subscribe to the podcast at iTunes, get the RSS feed, or listen via the media player above. You can also read the transcript, which includes credits for the music you’ll hear in the episode.)

So what are the three hardest words? Conventional wisdom suggests: “I love you.” Readers of this blog recently offered up their suggestions of challenging three-word phrases. In their new book Think Like a Freak, Stephen Dubner and Steve Levitt tell us that the hardest three words in the English language are “I don’t know,” and that our inability to say these words more often can have huge consequences.

On this week’s podcast, we explore where this unwillingness to say “I don’t know” comes from. Dubner talks to Amanda Waterman, a professor of developmental psychology at the University of Leeds. Much of her research (gated papers here and here) is about people’s unwillingness – especially children’s unwillingness – to say “I don’t know.” Waterman has found that the vast majority of kids pretend they know the answer to unanswerable questions.

WATERMAN: It has varied between studies, but you’d be looking at two-thirds to three-quarters of children—and we’re talking in the age range here of about five to eight years old—would say ‘Yes’ or ‘No’ to a yes/no question that we know they don’t know the answer to.

Apparently this is a habit that we adults don’t grow out of. You will hear Levitt tell Dubner that he has witnessed people’s reluctance to say “I don’t know” way too often:

LEVITT: So we wrote Freakonomics, and because it was deemed a business book and we sold a lot of copies, that made us business experts. And since we wrote that book I’ve been asked a ton to go talk to companies and give them advice. And what’s amazing to me is I could count on one hand the number of occasions in which someone in a company, in front of their boss, on a question that they might possibly have ever been expected to know the answer, has said “I don’t know.” Within the business world, there’s a general view that your job is to be an expert. And no matter how much you have to fake or how much you are making it up that you just should give an answer and hope for the best afterwards. And I have seen it teaching the business school students, that they are incredibly good — the MBAs — at faking like they know the answer when they have no idea.

Levitt goes on to tell the story of one multinational retailer he worked with whose inability to admit they didn’t know ended up costing them millions of dollars. Finally, you’ll hear his suggestion for how we can all get better at saying these three most difficult words.

Walter Clark

A company that can forgo millions by not having to admit "I don't know" can be put out of business by a less arrogant company who responded properly to "I don't know". But what if the entity has no competition and the cost of their operation is diffused because it is merely one agency among thousands all of whom draw from the same source of money? That entity perhaps should, with the power of a Constitution or something, not be allowed that monopoly. But that action can only take place with politics. The sacred institution of voting can't get around the constraint that the only ones to choose from are: new-comers who bubbled to prominence by never saying "I don't know" and incumbents who in addition to never saying “I don’t know” come from an environment where there is no feedback. Government is the use of force by those who were judged only by their good intentions.

Mike Frausto

I enjoyed this episode very much and agree that these 3 words are some of the hardest to say in the English language. However, I have to humbly disagree that they are the hardest. I believe the hardest words to say are "It's my fault". Given the blameless society that we live in, I'm sure you can find enough examples to fill 3 episodes. Your problem will be where to begin !! Banking... Politics .... environment ... Fat kids eating junk food.... I can go on for ever ! Look forward to your thoughts.

Paauilo Farmer

well, the kids are trying different things to see how the world is put together. actually i thought their answers were very creative and trying to make sense of the world about them. yellow is light and high and red is hell and heavier. loved that.

Carla Ceres

Nice episode, folks! OK, I don't know but... couldn't those children who were unwilling to say "I don't know" be thinking that it was just a game they were playing? Maybe they were just trying to give creative answers to silly questions.


I think your advertising example is way off base. The problem is not that they don't know: they do know, thanks to that intern. The problem is (to paraphrase Mark Twain) is not that they don't know, it's that they think they know something that just ain't so.

Enter your name...

They don't know. They don't know whether that was a one-time fluke, something that only affects Pittsburgh, something that only worked in that one year, or any number of other things.

They might have a vested interest in not learning that newspaper ads are useless for them (if, for example, designing newspaper ads is their primary job activity), but they don't know.

I would have been interested in taking this discussion up to the CEO. They're predicting the CEO's reaction to a program that might result in their ads being even more effective, or saving hundreds of millions of dollars by stopping them—and they don't think he'll be interested. The response to "the CEO will kill us" should be "Let's go ask him".


You misunderstand: what they do know is that advertising is necessary. They know it so well that they keep on knowing it in the face of contrary evidence.


Towards the end of the podcast, you talked about the company who wouldn't experiment with newspaper ads. The conclusion reached by Dubner was that marketing people would rather spend a billion dollars on useless advertising would than admit they don't know. My conclusion was different: that suspending newspaper advertising would look so bad to the higher-ups who control their jobs (because it was "obvious" to the higher-ups that newspaper advertising worked) that they would lose their jobs. Even worse, it's possible that they'd discover that newspaper advertising (and other forms advertising) wasn't worth the money that the company spends, and therefore, the entire marketing department would get cut (i.e. the marketing people would be destroying their own jobs).

So, maybe the problem isn't so much that the marketing people didn't want to say "I don't know" as much as the fact that any experiments they do leads to the possibility that they'll lose their jobs - either because the outcome of the experiments are "obvious" to the higher-ups (and therefore, the experiment needlessly cost the company revenue, and they should be replaced with marketing people who know what the CEO already "knows" about the effectiveness of advertising) or because it would show that advertising wasn't effective and the marketing people should lose their jobs (because the company was overspending on marketing).


Chris Land

I found this podcast to be really interesting. One of the concepts that is hammered into us in the Canadian Army is to say that we don't know when we don't know something. The second step in that is to go and look up the answer and get back to the person who asked it in the first place. I found the phase "I don't know" to be not nearly as welcome in the business world as in the Army.


I liked this podcast and completely agree that many problems could be solved if we could more often admit when we don't know. However, many times the opposite problem is also too relevant, in which "I don't know" has become an accepted way of stating that one would like to think no further, uttered under the guise of responsibly admitting one's own ignorance.

With that in mind, I agree that "I don't know" should be heard more often, but I also think that the vast majority of the time it should be accompanied by a "yet," or a "but let's figure it out." I continue to be amazed by how many times people are able to arrive at the answer to something they don't know simply by dropping the appearance of omniscience and slowly working with the things that they DO know.

Stacy Wright

I use the words "I don't know" quit a bit.....
It really helps takes the pressure off and it feels good not to go out on a wire to prove, that I am bearer of culpable knowledge. " I don't know", I may not be right, but I will never be wrong.

Actually, one of my favorite responses was "you guys are talking to me like I am some kind of expert here, but I really don't have any idea what I'm doing, I'm just figuring it out as I go along".

Plus I enjoy the response I get, when I tell someone "I dunno know".


You tell a kid a story. You ask the kid a question about the story and he makes up an answer because the facts aren't in evidence. In his mind, (or Levitt's mind "LEVITT: I’m sure they did. Doesn’t everyone listen to music?) he's helping you tell the story. You didn't put him under oath to tell the truth, the whole truth and nothing but the truth...


I really like this episode and I hope it encourages people to admit what they know and don't know.

I would like to add an aspect that I did not notice in the podcast (and I haven't read the book yet).
We live in a world full of information and it is already hard to filter. When people answer question with factoids, half-truths or guesses, they add noise to the system which is a vast disadvantage for all listeners. Instead an environment with more signal than noise, we can all concentrate better on the important things. And "I don't know" is faster than most other answers, except maybe "yes" or "no".

PS: I am not a native English speaker nor a linguist, but is "I don't know" not 4 words? ;-)


Loved this podcast. It really got me thinking of what company could be called the 'Freakiest?' I would propose that Capital One could be in the running. My understanding is that they love doing experiments. What other companies would you call 'Freaky?'


Levitt should practice saying this about the science of climate change. C'mon now "I don't know". (But the scientists do know!)


Something in this episode bothers me:
Nobody knows the answer to the 'unanswerable questions' which means EVERY ANSWER is correct. Children are especially more susceptible to just making up an answer because they have so much imagination. The only context one should say I don't know in is if there is a specifically correct answer. Like if you ask 'How many fingers am I holding behind my back?'.
Asking weather a jumper is more angry than a tree... The answer cannot be I don't know, whoever says that has no sense of logic. You could say 'That doesn't make sense' or just pick one depending on your feeling of the moment.


I work as a school psychologist and assess a lot of students with learning disabilities. I find that these students are often very willing to say "I don't know." That is often a common strategy for them to get through things in school. I think internally they get the sense that "I don't do well in school and if I say 'I don't know' then someone will tell me the answer quickly." These students when encouraged to take a guess often prove that they know much more than they or anyone else thought they knew.


technology will get rid of the word I Don't Know when we are all wearing Google glasses, but only b/c we will have BS detectors fact checking every spoken word.