The Strange Mystique Of The Number 'Seven' Seven has long played a fascinating role in the sciences, psychology, mathematics and religion, and has uncanny usefulness as an organizing number. In Seven, Jacqueline Leo explores the cultural significance of the number.
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The Strange Mystique Of The Number 'Seven'

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The Strange Mystique Of The Number 'Seven'

The Strange Mystique Of The Number 'Seven'

The Strange Mystique Of The Number 'Seven'

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Seven has long played a fascinating role in the sciences, psychology, mathematics and religion, and has uncanny usefulness as an organizing number. In Seven, Jacqueline Leo explores the cultural significance of the number.


As far as numbers go, 13 pales in comparison to seven. Seven days of the week. Seven sisters. Seven dwarfs. Seven wonders of the world. And yes, the list goes on, probably in multiples of seven. Of course, there's Mickey Mantle, too.

Coincidence? Author Jacqueline Leo thinks not. Her new book recounts the many ways seven figures in the sciences, psychology, math and religion, but she also focuses on this prime number's usefulness as an organizing tool. It is, more or less, about as many digits or grocery list items as we can reliably store in our in our noggins.

So tell us your seven story. Do you write out your to-do list in sevens? Swear by a seven-layer cake? Give us a call: 800-989-8255. Email us: You can also join the conversation on our Web site. That's at Click on TALK OF THE NATION.

And Jacqueline Leo joins us from our bureau in New York today. Her new book is titled, what else, "Seven."

Nice to have you in the program.

Ms. JACQUELINE LEO (Author, "Seven"): Thank you.

CONAN: And you cite a seminal study that suggest that seven measures our ability to manage information.

Ms. LEO: Well, yes. That was Dr. George Miller. He was a psychologist at Harvard when B.F. Skinner was there. And, of course, B.F. Skinner, the behavioralist, took all the headlines. But Miller was working on cognitive science. In fact, he's known as the father of cognitive science. And he did a number of tests and experiments that proved that we can only hold seven independent things in our short-term memory. And what he meant were letters, numbers or words. If they were more complex and if you chunked them together, you could remember many more.

For example, if I said, A, C, I, F, B, L, you would probably remember those letters. But if I chunked them into FBI, CIA, AFL, CIO�

CONAN: Mm-hmm.

Ms. LEO: �you would have many more to remember.

CONAN: So that's why we can now remember the 10 numbers in our phone numbers.

Ms. LEO: Right. But it started with seven, Neal. The area codes were added much later. And it's - there is a lot of speculation that it was Miller's study that drove the number seven into most telephone lines.

CONAN: But you cited the title of his study, and I think it was "Seven, Plus or Minus Two."

Ms. LEO: That's right. Because, you know, some of us are a little better at things than others, I guess.

(Soundbite of laughter)


Ms. LEO: Me, I'm getting closer to three these days.

(Soundbite of laughter)

CONAN: Well, I can't remember my Social Security number, which is nine. But it's a struggle. I'll grant you that.

So how does seven help us organize our lives?

Ms. LEO: Well, for starters, you have to realize that we're overwhelmed with not only digital noise and a lot of choices out there. I'll give you an example. If you go to a grocery store, even in a recession like this, you'll see 26 different kinds of Tide. If you really want to get every single thing in your hamper clean, you'd have to probably buy all 26.

How do you absolutely function with those choices in front of you? Or if you want to buy orange juice? There is 17 different kinds of Tropicana orange juice. And you're not going to buy, you know, every different one and you'll never have room in your refrigerator.

So look at the number seven and say, well, I'll try the juice boxes instead.

(Soundbite of laughter)

Ms. LEO: And you can, in fact, store seven of those. You can decide which ones you like, and�

CONAN: But they come in six-packs.

Ms. LEO: Yeah, well, there's that.

(Soundbite of laughter)

Ms. LEO: Some of them do, and some of them you can get individually.

CONAN: Mm-hmm.

Ms. LEO: The point really is that in order to organize everything that's coming at you so quickly and so dramatically and to avoid what I call mental hopscotching in today's world, especially among young people, it's really important to just say no. No, I'm not going to turn on my email and have that little ping every five minutes because if I do, I will - it will take me 15 minutes - and this is proven - to get back to what I was really doing and regain my focus. Or I'm not going to be on the phone crossing the streets so I don't get hit by a car - or things like that, where you can actually let your brain idle and daydream and internalize some of the sense and images and stimulation that you've had for the last couple of hours.

CONAN: And this is not just to help us organize our lives more efficiently. You say this is a matter of great economic import.

Ms. LEO: Well, it is. I mean, part of it has to do with how we retain information, how we learn, and whether or not we're going to have a civil society. One small example of civility that seems to have gone out the window -aside from the way people deal with email - is a study that was done and was framed in a book called "Distraction," which was written by Maggie Jackson. And she determined that only one-third of the people who were surveyed, women in particular, says hello or even recognized their spouses or their partners when they came into the room.


Ms. LEO: So, you know, home from work or wherever it might have been. There's just like a total ignoring of other people when you have your BlackBerry, your computer, your television, your iPod or whatever on. And because we're always on, we're becoming a nation of grazers of information. We're not really going deep enough to find what you might call truth about an issue.

CONAN: There's a sad chart in your book in which you list, well, how many times do you forget - you go into a room and forget what you came in for. And you compare older and younger people. And I say it's a sad chart because the numbers for the older people are very high, and I can count myself in all of those categories. The sad part is all the younger people's numbers aren't that much better.

Ms. LEO: Well, that blew me away, too, because my daughter - who's 27, who loves books and is actually an editor at the Huffington Post - but she actually had a book club. She loves reading, you know, wonderful, lengthy books. And she said about, a year ago, mom, I can't seem to concentrate. I read two paragraphs, and my mind begins to wonder. And I said, well, what are you going to do about it? And she said, well, I'm going to turn off TV. I'm going to, you know - and she said, I'm going to retrain my brain. And this was her answer to this, and she succeeded. Now, I don't know if she's still succeeding, but she certainly did then.

And then I said I wonder about, you know, a lot of other young people. So I did a - what you might call - a mother-in-law test. It wasn't scientifically proven, but I did send out the same survey to older people and younger people that I knew and got those results. And I was shocked, as well. You know, we're turning - these young people are tuning into old people very quickly.

CONAN: So was it the book your daughter was having trouble reading - was it "The Seven Secrets of Efficient People"?

(Soundbite of laughter)

Ms. LEO: Yeah. I don't think so. It's probably "War and Peace" or something.

CONAN: Let's go and get some callers in on the conversation. Kayla is with us, Kayla calling from Phoenix.

KAYLA (Caller): Hi. I love the number seven. I think it's a really - as an odd number, I guess, it's a very even odd number. It completes a lot of things. I remember things easier in groups of seven. But my friend, just the other day, like last week, and we were going over to another friend's house, and I knocked on the door and she laughed at me because I knocked seven times. And I guess she noticed that when I come to her house and I knocked on her door. And she was, like, do you always knock seven times? And I had no idea, but I guess she knew, because I just - it's a really good number.

CONAN: Did you go bop ba da bop bop, bop bop?

(Soundbite of laughter)

CONAN: A shave and haircut, two bits. It's seven.

KAYLA: No, but I�

Ms. LEO: There you go.

KAYLA: When she said that, I guess I was, like, well, I guess I kind of like counted out in my head, like one, two, three, four, five, six, seven. And it's a just - it's a good knock. Like anything less than that just doesn't - I'm like, well, they couldn't - they might not have heard that. Anything more than that sounds really incessant and annoying. So�

(Soundbite of laughter)

Ms. LEO: Well, you make a�

KAYLA: Seven is a nice number.

Ms. LEO: You make a great point, because when you ask people to name a number between one and 10, the number seven comes up overwhelmingly, in study after study.

CONAN: Ah, just Mickey Mantle fans.

Ms. LEO: Well, they do�

KAYLA: Yeah. I love - like when I did - I had this thought between picking a number between one and seven with my kids because I'm always thinking the number seven, and I think they caught on to that.

(Soundbite of laughter)

CONAN: There's the weakness, too(ph).

KAYLA: So I had a thought, we have to make it between one and 15 and like pick a different, random number. But, you know, I just think as far as odd numbers go, seven is a really nice, round, whole number.

(Soundbite of laughter)

CONAN: Thank you, Kayla.

Ms. LEO: Well, it's that and it's true. And it's also a prime number, and without it, we couldn't have the encryption we have with our ATM machines, among other things.

CONAN: Well, so is 13. A lot of prime numbers.

Ms. LEO: Yeah.

CONAN: Yeah. Let's get Kai(ph) on the line, Kai with us from San Francisco.

KAI (Caller): Hi, Neal. Thanks for taking my call.

CONAN: Sure.

KAI: I just wanted to point out the number seven as it relates to this game Scrabble. And I heard once that the people who invented the game picked the number seven as their tile number intentionally. And it became quite obvious when Scrabulous, the Facebook Scrabble, when they got sued and had to change their game to eight tiles, that the game just really went downhill after that, it seemed like.

CONAN: The seven tiles - when you start the game of Scrabble, you start with -each player has seven tiles. And however many you put on the board, you always pick out that number, so you always have seven on your little easel there, I guess it is.

KAI: Yeah. And when you play Scrabulous, you then have to pick eight tiles, and they changed the layout of the board. And it just - it really doesn't seem to work as well.

CONAN: And, of course, a bingo in Scrabble is using all seven letters, and you get 50 points extra and all that good stuff. So�

KAI: And you're really happy doing that. Yeah.

CONAN: Though as rare as it may be.

KAI: Exactly. Well, thanks so much.

CONAN: Thanks very much for the call. And it's interesting, in your book, "Seven," Jacque Leo, you have a puzzle by the puzzle master.

Ms. LEO: I do, indeed. Yes, Will Shortz. And I've known Will for a while, and he did a column for us at Reader's Digest when I was there. And he very generously did this seven - this simple seven puzzle for this book.

There's a lot of entertainment in the book. I mean, some of it's really fun, and I really had a great time researching it. I mean, I found that, you know, there were seven ingredients in a Big Mac, which I had forgotten, and that things like, you know, Paul Simon's wonderful song "50 Ways to Leave Your Lover," there's really only seven in that song.

CONAN: Ah-ha.

Ms. LEO: So you come up with funny things and oddities that made the book, I hope, a little entertaining for folks.

CONAN: Does the - do the seven ingredients in a Big Mac count the special sauce as one?

Ms. LEO: Yes, it does.

CONAN: Okay. Then I think we could get into an argument there.

Ms. LEO: I agree. We didn't parse the sauce.

(Soundbite of laughter)

CONAN: We're talking with Jacque Leo. Her book is called "Seven: The Number for Happiness, Love, and Success." 800-989-8255. Email us: And you're listening to TALK OF THE NATION from NPR News.

Let's go next to Peter, Peter with us from Berkeley.

PETER (Caller): Hi. Well, at first, my disclaimer: This is mainly just for fun - like the show, I guess, today. But in my family of origin, there are seven kids. I'm number five. And for the last three years, we've had a reunion on our parent's anniversary every year. And we've always gotten five, so we call it the fabulous five. But it seems to me, there would be a great power to get all seven of us on the same phone conference call. And I think that would be a great goal. I mean, there's an importance to family solidarity.

CONAN: Indeed.

PETER: So this is just, you know, again, just for fun. And also, remember that childhood rhyme: One, two, three, four, five, six, seven, all the children go to heaven?

Ms. LEO: That's not a bad one.

(Soundbite of laughter)

CONAN: OK. Good luck getting all your relatives on the phone at the same time, Peter.

Ms. LEO: Well, you know, speaking of relatives, Neal, there's a story by Kristin van Ogtrop, who is the editor-in-chief of a magazine called Real Simple, which is appropriate for this book. And she was so happy growing up with the uncles and aunts that formed the seven people, the seven siblings in her father's life, that when she had her own family and had two children, wonderful children, she felt something was missing. And so, she wound up with another one just to try to fill out the table. I mean, she just recalled these wonderful get-togethers. So our caller was right on the money there.

CONAN: Let's get another caller on the line. This is Rachel, Rachel with us from Wichita.

RACHEL (Caller): Hi.


RACHEL: Can you hear me?

CONAN: Yes. Go ahead, please.

RACHEL: Okay. Well, I just wanted to comment that since my husband entered my life, the number seven has really seemed to crop up in really important dates in our life. I didn't realize it until the previous caller said it, but he also had seven siblings in his family, five brothers, two sisters. And also, we were married on January 7th in Nepal. Our second marriage was in this - on July in the United States. Our first child was born on 7/7. And a major surgery in my life was rescheduled, and I had a feeling that it was going to be rescheduled to a seven. I just had a feeling, and it was. It was rescheduled to a seventh day. And I just have - also have a feeling that our next child is going to be born on the seventh day of the month.

And I've really found that - that's more than an important for me in my life. I found that a lot of the important things in my life have revolved around it. And I thought it was just me. But I'm happy to hear that there's a lot of other people.

CONAN: Rachel, I have to tell you, you're calling on line seven.

Ms. LEO: Wow.

RACHEL: I'm sorry?

CONAN: You're calling on line number seven. We have seven lines, and you're in line seven.

RACHEL: Oh, my gosh. Are you kidding me?

CONAN: Nope. There you are.

(Soundbite of laughter)

RACHEL: Oh, my gosh. See? That's what I'm talking about. Everything like that happens, and people are like, oh, it's just number seven. And they - I thought it was - maybe it is just me. Maybe the universe of seven is just revolving around me or something. I don't know. But it's just really - I just thought it was very interesting that you guys have the show, and thanks for the topic.

CONAN: All right. Thanks very much, Rachel.

Here's an email we have from Michael in Mishawaka, Indiana: While practicing, the University of Notre Dame hockey team members all wear jerseys adorned with the number seven - no other personally identifiable numbers and name, just sevens on everybody's jersey. Team members are sworn to secrecy as to the exact meaning of those sevens. But one would suspect it has something to do with team building and bonding. Many of us do hope to be the one who discovers the actual secret behind the sevens.

Were you aware of the Notre Dame hockey team's peculiar numbering process?

Ms. LEO: Not me. But I do know about the Secret Seven Society. I don't know enough about it, because nobody will talk about that, either. It started at the College of William & Mary many, many years ago. And when I told some people at Wesleyan University here in Connecticut that I was writing this book, one of the graduates said, well, do you know about the Secret Seven Society? And I said, no, tell me. And she said, I can't. I'm a member.

(Soundbite of laughter)

Ms. LEO: So there you go. But there is a - there are books about it, and it's apparently a charitable or philanthropic organization that is based on bonding and good works. And that's all I could find out right now.

CONAN: Probably gather to watch Ingmar Bergman's "The Seventh Seal" every�

Ms. LEO: Oh, boy. That'll - that's the best�

(Soundbite of laughter)

CONAN: Or Brad Pitt in "Se7en."

Ms. LEO: Yep.

CONAN: Yeah.

Ms. LEO: There was that major movie. But there were a lot of fun movies with seven, too, from "The Seven Year Itch" to the "Seven Brides for Seven Brothers." And there's really a litany of movies that have it, including "The Magnificent Seven," "The Seven Samurai," and on and on.

CONAN: And indeed, "Snow White and the Seven Dwarves."

This email from Tim in Charlottesville. I'm an artist, age 59. I recently discovered that almost every address of my living quarters and my studios over the years have had the number seven in them - not only that, but one, zero and seven: 701, 107, 1709, 3701, et cetera. I haven't the slightest bit of superstitious chromosomes in my body, but it does seem curious.

Well, if you'd like to explore that curiosity, you could do far worse than to read "Seven: The Number for Happiness, Love and Success" by our guest, Jacqueline Leo, who joins us today from our bureau in New York.

Thanks very much for being with us.

Ms. LEO: Thank you, Neal.

CONAN: This is TALK OF THE NATION from NPR News. Hey, that's seven words. I'm Neal Conan, in Washington.

Copyright © 2009 NPR. All rights reserved. Visit our website terms of use and permissions pages at for further information.

NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.

Excerpt: 'Seven'

Cover of 'Seven'

Eliminating options, no matter how much sense it might make at a given time, is a challenging undertaking. One reason is that we're all gamblers at heart. When we do a Google search and get 500,000 results, we don't quit after the first page or two. We think there's gold in those hills. So we dig and dig and before long we've wasted an hour or two and, as a bonus, we have a stiff neck. Besides, it's nearly impossible to eliminate possibilities. Because shutting doors — closing ourselves off from work, friends, information, tools, and -entertainment — doesn't fly. Dan Ariely, a professor of behavioral economics at MIT, says that's because we're stuck in a "just in case" mindset. He says we buy multimedia computers even though we'll never record a podcast or a video; drive SUVs even though we'll never go off-road; overschedule our kids with after-school activities even though they could learn a lot (or even more) playing freely with other children. But we do it "just in case" that piano lesson unveils a hidden prodigy. Ariely wanted to know why people were reluctant to commit to a given choice and thus eliminate other options. So he teamed up with Jiwoong Shin, a professor at Yale, and created the "door game."

The game was a computer program showing three doors: red, blue, and green. Students were given 100 clicks. Each time they entered a room, they could earn between 1 cent and 10 cents. Every time players switched rooms, they used up one of their clicks. If a room was not entered after twelve clicks, it would disappear. As the game progressed and doors diminished in size, warning players that they were about to disappear, students would revive the doors by clicking on them even though they weren't "money clicks." The players' stress levels increased, but their winnings didn't. Had they chosen to stay in one room, they would have earned more money — an interesting metaphor for life today.

Ariely calls keeping all your options open irrational excitement. Why irrational? When the students were given the equivalent of a "cheat sheet" (that is, they were told what kind of winnings to expect from each room and given time to practice) the results did not differ from the original outcomes. They did not allow the doors to close because they experienced it as an emotional loss. They became prisoners of their own choices.

Type "Internet" into Google and you'll find nearly two billion links to pore over; where are you going to even start? At, say, one minute per link, it would take more than 2,000 years to complete your search. Where is Mel Brooks's 2,000-year-old man when you need him? Or walk into a Home Depot and see how long it takes you to compare the 164 different screwdrivers they sell — and don't forget to include the near-microscopic set included in the eyeglass kit at the checkout counter.

Consider the following:

There are over 100 million blogs that even the bloggers' mothers don't have time to read.

Tropicana orange juice choices went from two (container and frozen) to more than seventeen: orange pineapple, orange tangerine, orange strawberry banana, Pure Valencia, Pure Valencia with Pulp, Pure Valencia with Mango, low acid, Healthy Heart, Healthy Kids, Antioxidant Advantage, Pulp Free Calcium plus Vitamin D, High Pulp plus Calcium, Light 'n Healthy with Calcium, Light 'n Healthy with Pulp, High Pulp, Some Pulp, No Pulp.

And if you wanted to treat every piece of clothing you own with the respect it deserves, you'd have to buy twenty-six different detergents from Tide alone.

There's an old joke about a new immigrant who was learning to speak English. He would stop at a coffee shop each day and order the same thing: apple pie and coffee. One day his friend said in their native tongue, "Why don't you try a little variety? Order a ham sandwich and coffee." The newcomer was grateful for the advice. So the next day he went to the coffee shop and told the waitress, "Ham sandwich and coffee." She said, "Do you want that on white or rye?" He replied, "Apple pie and coffee."

How many times have you felt like the immigrant when you've walked into a Starbucks and found yet another exotic choice from Sumatra or Madagascar served as caramel macchiato?

Unless you're an expert, it's the same confusion you experience at a fine restaurant when the waiter hands you the wine list at the beginning of the meal, or brings the tea box at the end. Yes, tea is the new coffee, and at Hina's in Sacramento, California, you have your choice of over 250. The owners acknowledge that the sheer number of teas is at first overwhelming to their customers, so they provide information and tastings to help them distinguish among the choices.

No wonder John Maeda titles the introduction of his book "Simplicity = Sanity." The American Psychological Association would agree with him. In a series of experiments published in the Journal of Personality and Social Psychology, researchers, headed by Kathleen D. Vohs of the University of Minnesota, found that making many choices impairs self-control. They determined that making a choice uses the same brain resources that are used for self-control and active responding. The more subjects were forced to make choices among products, courses of study, and other options, the less they were able to meet deadlines, possess physical stamina, or soldier on against adversity. In short, too many choices paralyzed the subjects.

Why has Google become the dominant search engine on the Internet when it was launched four years after Yahoo!? Take a look at the opening pages of Google and Yahoo! and decide which is simpler, easier to focus upon, and easier to use.

To this day, experts claim that Apple would have dominated Microsoft in the world market if Steve Jobs had opened his operating system to software developers early on. Talk to anyone who owns a Mac and they'll tell you that it's a more elegant machine with a friendlier interface than a PC. Buy an iMac, plug it in, push one button on the back of the screen, and you're ready to use your new toy. Buy a desktop and it's an hour — at least — crawling around on the floor as you fiddle with the power adaptors of the multiple components. People have responded to Apple's simple design by increasing Apple's computer market share.

For average consumers, a successful technology product is simple and intuitive, something even a child could use. Of course children have set the rules when it comes to judging the value of a new gadget, game, or tool. Their mantra is: "If I have to read the manual, it wasn't built right." They, like us, want to keep things simple.

Here are seven simple ways to a smarter, simpler life:


YES: Ask for help, pay for help, or say yes to an offer of help.


NO: Learn how to say no to too many social engagements, too many favors, too many extra projects at work; too many irrelevant solicitations from spammers and direct mailers.


STOP: The clock. Life isn't a 24/7 merry-go-round. If it were, you wouldn't get the seven hours of sleep necessary to keep you fit and sane.


GO: Keep in shape with an exercise routine you can stick to.


START: Use technology so it doesn't use you up. Online banking, for instance, will save you time, money, and stress because your mortgage will be paid automatically.


END: Clear the clutter, trash the trivial stuff. Get organized.


BE: Make time for friends, lovers, family. Learn how to breathe and daydream. Be your true self and find your humanity.

Excerpted from the book Seven by Jackie Leo. Copyright © 2009 by Jackie Leo. Reprinted by permission of Twelve, a Division of Hachette Book Group. New York, NY. All rights reserved.

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