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.

Jon "maddog" Hall

I had a boss who could not say the words "I was wrong". Even his wife privately admitted that she had never heard him say those words.

One time I caught him in a trap where the only response he could give was "I was wrong".

His face turned red and he had trouble breathing. I thought he was going to have a heart attack. He finally spit out the words "maddog, you were right", which (given the situation) was the same as him admitting he was wrong.

But he could not say those words.

I told the man he should seek out psychological help.


I tend to think of young children as naturally scientific - that is, they are ALWAYS trying stuff to see what happens & when something works to their advantage - or they like an outcome - they will repeat until it doesn't anymore - & then even for awhile longer to verify.

Also, it's hard to say that children are actually "afraid" to say they don't know something - thinking that's a bit of a projection. Young children often just make stuff up - many haven't yet grasped the difference between what they WANT to be true & what IS true.

Joey Melliza

This kinda reminds me of Socrates' "I know that I know nothing," --- which is like a gateway for more inquiry and ultimately to knowledge.

Mark Sauerwald

I enjoy your podcast, and have bought the new book, but haven't read it yet...

I am an engineer, and have worked most of my career providing technical support for semiconductor products, as well as managing people who do the same. In the old days, when most of the questions came over the phone, it was very important to know when you didn't know the answer to a question and to be able to say "I don't know, I'll research it, and get back to you". As a result, when interviewing candidates, I would always try to get them to say "I don't know" in the interview. As you would know, most of the candidates were not able to jump that hurdle.



I really enjoyed this Podcast and write a blog post on this very topic with a link to this site. Enjoy!


My favorite part was towards the end when Amanda Waterman was asked what kind of effect a cultural shift towards saying "I don't know" more often may have, and Amanda responded with several sentences all prefaced with "I suppose", "I guess", "perhaps" and other uncertainty qualifiers.

Perhaps she should have said "I don't know." :-)

Martin Azevedo

I love the show, and I agree it's vitally important to be able to say "I don't know" - but the research with the kids was very silly.

The kids had a tremendous incentive to make something up (Fun! Creativity! Showing off!) and no incentive whatsoever to say "I don't know" (Boring! Unimpressive! Surrender to mundane authority!).

Saying "I don't know" at work can summon needed guidance and help, but saying "I don't know" when asked about a silly story is passing up a fun game for a disappointing one. Follow the incentives!

Dan Palmer

I rarely pretend to know what I don't. But then again, I am a historian and a good historians know only one thing...that they can never know everything.

C Scyphers

I was listening to this podcast today and I wanted to pass along something from my corporate experience. Specifically, when I hire people, I will only hire people who say "I don't know". Let me explain.

I work in IT. Big Data to be precise. It's a burgeoning field, with new things coming out every week, not to mention that to be good at it, you have to have deep knowledge of programming, statistics/mathematics, and business acumen in general. With that in mind, I will take some point in the interview and keep drilling down on a given topic until the person either admits they don't know or it becomes clear they're never going to make such an admission. The people who fall in the latter camp will never work for me under any circumstances.

My reasoning is that my field is too broad, too dynamic, and just generally too complex for any one person to know everything about anything all the time and always be right. And, if you're going to try to snow me during an interview (where it's somewhat high stakes but not life or death) you're going to try to snow me -- or worse, a customer -- when you're on the job and the stakes will be higher.


Don Montanaro

Great podcast. Thanks for kicking off an excellent discussion!

As CEO of online brokerage TradeKing, I’ve encouraged our troops from day one to admit when they don’t know something, even (and especially!) when speaking with clients. That’s not always a comfortable or automatic stance to adopt when you’re responsible for people’s money. But we swear by it.

Our policy is simple: as a TradeKing employee, you’ll never get dinged for saying “I don’t know,” provided you also do two things. First, you turn right around and find out the correct answer. Second, you make it your business to spread that answer around to anyone on your team who’d find the info useful. That way, everyone wins: our clients know they can trust us to provide complete, accurate answers, always. The person who doesn’t know empowers him or herself to learn something new, and everyone on our team gets smarter and better informed. Plus it’s liberating and stress-relieving not to bluff your way through life – our clients seem to agree with that, too.

I blogged about this subject in the past - see “The Business Value in Saying I Don’t Know”

Thanks again for sticking up for these three little words. They shouldn’t get folks in hot water as often as they do.

Be good,
Don Montanaro
CEO, TradeKing Group

TradeKing Group, Inc. ( consists of companies that provide online brokerage services, social communities for investors, investor education and more. Its subsidiary, TradeKing, LLC, is a nationally licensed online broker/dealer dedicated to empowering the independent, self-directed investor; member FINRA and SIPC.

Investments involve risks, and online trading may not be suitable for all investors. Please see TradeKing’s website for important information on risks and suitability, and contact TradeKing with any questions or inquires.


Don Montanaro

Here is the link to "The Business Value in Saying I Don't Know" -

Here is a link to my YouTube video on the subject -

Rather Not

This is funny because I had a habit of saying "I don't know." I figured out it was something I said as a filler and also when I was being lazy about thinking about the answer ans saying it out loud. Even my therapist gave it to me as an assignment to stop saying "I don't know." Even my father pointed out that I said it to him to often. After watching my mother and my baby nephew ask questions such as "Why is the sky blue?" and hearing my mom say, "I don't know." I'm guessing I might have picked up the habit from her!


Notice that Levitt also gave attempted answers (not "I don't know") to the picnic questions. The natural answer to the story teller's 'trick' questions are "I can't know", not "I don't know". The story was simple enough, and these kids (and Levitt) seemed to me smart enough to spot that they were being asked "can't know" questions - by an adult who also would also have understood that they were 'cant know' questions.

So what does a poor kid do? Treat this game as either an imagination exercise and make something up, or just say anything that might pacify the interrogator - who never confirms or denies your answers anyway.

It seems to me that most experimental formats for discursively eliciting this kind of human task disposition will suffer from unacknowledged 'demand characteristics'. In fact, to take it further - much of the behavioural economics tradition of empirical work seems to fall victim of an insensitivity to the social psychology of participating in experimental procedures. But, keep up the good work!


Elizabeth Davies

I learned quite early and sadly that daring to say "I don't know" to a professional supervisor, while in training, resulted in being considered incompetent and unworthy of being taught anything. The supervisees who barreled on through, blithely faking knowledge, were considered competent.

Once I became a full-fledged professional myself, dealing with people who had health-related issues, I was able to resume saying quite honestly, when necessary: "I don't know." I would then explain why the problem was so complex and thorny, detail what I'd considered and why what I'd found thus far didn't quite seem to fit, and give them new leads to follow in the search for a solution.

I also figured out that my old supervisors hadn't known the answers themselves and had no idea how to teach me--that's why they'd been so determined to put me down... to save face. They were the incompetents, not me.



Linking off of some of the other comments, I am also a teacher and have often noticed how reluctant teachers are to say "I don't know" when asked questions by students. I know of some teachers who will just make up answers that are completely wrong rather than say those words and then when confronted with evidence or facts that seem to disprove their statement will say that the facts/evidence are simply wrong.

It has always struck me as strange that this happens. What's wrong with not knowing? Yes, I'm the teacher, but does anyone really expect me to know EVERYTHING? Or really does anyone expect you to know everything on any one topic? I've never thought that and I've always thought that at least some of my good report with the students is that I am will to say I don't know.

A related idea that I also try to overcome in my classroom is students willingness to guess and be wrong. The small kids in the podcast were clearly willing to make up answers they didn't know the answer to. But in my high school class, instead of giving a guess, my students would rather sit there stony faced and quiet rather than hazard a guess and risk being wrong.

I specifically talk about this in class the first or second day and make a point of telling my students it is okay to be wrong. We are learning a topic that they probably know very little about, but I'd rather they guess and be wrong (but contribute to the conversation/discussion) than say nothing. Because if you are wrong, then we can look at the answer and see why it is wrong and use that to find out the right answers. With some students I am successful and they are willing to guess every time but there are others who won't believe me and will continue to stay silent.


Nabil Chowdhury

what is the hardest word in the world (English) PLS.................................!!!!!!!!!!!!!!!!!

Audrey L

I was gonna guess they were "I was wrong," but I suppose that could be considered a related phrase :)