• Skip to main content
  • Skip to primary sidebar

Tracking Health and Wellness Applications of Brain Science

Spanish
sb-logo-with-brain
  • Resources
    • Monthly eNewsletter
    • Solving the Brain Fitness Puzzle
    • The SharpBrains Guide to Brain Fitness
    • How to evaluate brain training claims
    • Resources at a Glance
  • Brain Teasers
    • Top 25 Brain Teasers & Games for Teens and Adults
    • Brain Teasers for each Cognitive Ability
    • More Mind Teasers & Games for Adults of any Age
  • Virtual Summits
    • 2019 SharpBrains Virtual Summit
    • Speaker Roster
    • Brainnovations Pitch Contest
    • 2017 SharpBrains Virtual Summit
    • 2016 SharpBrains Virtual Summit
    • 2015 SharpBrains Virtual Summit
    • 2014 SharpBrains Virtual Summit
  • Report: Pervasive Neurotechnology
  • Report: Digital Brain Health
  • About
    • Mission & Team
    • Endorsements
    • Public Speaking
    • In the News
    • Contact Us

Mind Teaser: Consider Linda

June 30, 2008 by Alvaro Fernandez

(I hope you enjoy this very reveal­ing mind teaser!)

Please con­sid­er Lin­da, a 31-year-old woman, sin­gle and bright. When she was a stu­dent, both in high school and col­lege, she was deeply con­cerned with dis­crim­i­na­tion and social jus­tice, and also par­tic­i­pat­ed in anti-nuclear protests.

Which is more prob­a­ble about Lin­da’s occu­pa­tion today? (a) Lin­da is a bank teller; (b) Lin­da is a bank teller and active in the envi­ron­men­tal movement.

Quick, what’s your answer? (a) or (b)?

—

If you answered (b), you are wrong, and in good com­pa­ny. That’s what most of my col­leagues and I answered the first time we saw this teas­er in one of our Stan­ford Orga­ni­za­tion­al Behav­ior classes.

It is more prob­a­ble that Lin­da is a bank teller, which is a whole cat­e­go­ry, that she is both a bank teller AND also active in the envi­ron­men­tal move­ment, which is a sub­set of that whole category.

A recent Wall Street Jour­nal arti­cle explains the phenomenon:

Free to Choose, But Often Wrong:

“When psy­chol­o­gists Daniel Kah­ne­man and the late Amos Tver­sky con­duct­ed an exper­i­men­tal sur­vey in the ear­ly 1980s ask­ing peo­ple to answer this sim­ple ques­tion, they dis­cov­ered, to their sur­prise, that most respon­dents picked “b,” even though this was the nar­row­er choice and hence the less like­ly one. It seems that salien­cy in this case, Lin­da’s pas­sion­ate polit­i­cal pro­file trumps logic.”

Relat­ed read­ing and teasers:

- Why Smart Brains Make Stu­pid Decisions

- 50 brain teasers to test your cog­ni­tive abil­i­ty.

Share this:

  • Tweet
  • Email
  • Print
  • More
  • Share on Tumblr
  • Pock­et

Filed Under: Brain Teasers Tagged With: Amos-Tversky, Brain Teasers, Daniel-Kahneman, Decision-making, Linda, logic, mind-teasers, Organizational-Behavior, saliency, smart-brains, smartbrains

Reader Interactions

Comments

  1. Devin says

    June 30, 2008 at 8:49

    This isn’t entire­ly true. 

    I think the orig­i­nal researchers over­looked the fact that peo­ple would assume that the stat­ed “fem­i­nist” clause in the sec­ond option implied that the first option did not include this eventuality.

    It would be like ask­ing whether you want an apple or an apple and a banana. Most peo­ple would assume that the first option does not include an banana. Very few peo­ple would ask whether I want­ed an apple, and then give me an apple and also a banana.

    So, accord­ing to most per­cep­tions, the options are “bank teller and NOT IN the fem­i­nist move­ment” or “bank teller and IN the fem­i­nist movement”.

    So it’s more that poor phras­ing influ­enced logic.

  2. Rangoli says

    June 30, 2008 at 9:01

    I agree with Devin.

  3. Malfist says

    June 30, 2008 at 9:06

    I agree with Devin too, but log­ic does not include assump­tions. There­fore, strict­ly log­i­cal­ly speak­ing, the answer would have been A. Which is easy enough to get if you’re think­ing and on your toes, how­ev­er most tests require ‘the best answer’ which would not be A. Who’s fault is it that we don’t get this right more often?

  4. Devin says

    June 30, 2008 at 9:23

    Mal­fist:

    All log­ic includes assump­tions; we call them axioms. 

    Lan­guage is very bad at rep­re­sent­ing log­ic in any form, so we’re forced to guess at the assump­tions behind the alter­na­tives we’re offered. Most of the time, the heuris­tic I men­tioned above works for us.

    I sus­pect you could unam­bigu­ous­ly ask this ques­tion in a con­struct­ed lan­guage like Lojban, which is designed for that pur­pose. I won­der what peo­ple would say then?

  5. David Osborne says

    July 1, 2008 at 6:22

    I won­der how many peo­ple used the same “log­ic” I applied. If I say “banker”, I can be 100% right or wrong; if I say “banker” and “fem­i­nist” I have a chance to be 50% right if she is either one. I have two chances to get some part of the ques­tion cor­rect based on a guess about occu­pa­tion and poten­tial fem­i­nist choic­es based on polit­i­cal activism at an ear­li­er age. Does this make any sense?

  6. Alvaro says

    July 1, 2008 at 8:28

    Good dis­cus­sion.

    Mal­fist: exact­ly, “you’re think­ing and on your toes” is anoth­er way of say­ing “you are ful­ly engaged in ratio­nal deci­sion-mak­ing”, not let­ting your­self be car­ried away by the phras­ing of the question.

    Devin: I agree that lan­guage is imper­fect, and a for­mal log­ic rep­re­sen­ta­tion of the prob­lem would ren­der the solu­tion obvi­ous. But I dis­agree with your con­clu­sion. The prob­lem is not lan­guage itself. Lan­guage is lan­guage. Lan­guage does­n’t have a brain. We do have a brain, and need to know how it works…including how not to be car­ried away by assump­tions when we don’t want to.

    Per­haps we should ask Lin­da about all this 🙂

  7. sumanth says

    July 2, 2008 at 10:03

    Davis:
    well, your log­ic would be apt if sec­ond choice was ‘banker’ OR ‘fem­i­nist’ than ‘banker’ AND ‘fem­i­nist’. 🙂

  8. Devin says

    July 3, 2008 at 7:51

    I’m back!

    Alvaro: I believe that lan­guage is the prob­lem. We do have the abil­i­ty to inter­pret lan­guage, but we inter­pret it in a way that works most of the time. As I said, the heuris­tic I iden­ti­fied works most of the time with most nor­mal communication.

    The fact that the solu­tion would be obvi­ous if rep­re­sent­ed using anoth­er form of com­mu­ni­ca­tion (per­haps a Venn dia­gram) means that the form of the ques­tion is the rea­son for the con­fu­sion, and not the log­ic itself. We sim­ply don’t expect peo­ple to com­mu­ni­cate in Eng­lish the way this ques­tion is asked, and this is a rea­son­able expec­ta­tion. Any ordi­nary Eng­lish speak­er would make the same con­clu­sion about the apples and bananas.

    The fol­low­ing XKCD com­ic sums up my view about this question:

    http://xkcd.com/169/

  9. Non says

    July 7, 2008 at 6:26

    Devin: You think peo­ple assumed the options were: “bank teller and NOT IN the fem­i­nist move­ment” OR “bank teller and IN the fem­i­nist movement”.

    So peo­ple choose the sec­ond because OBVIOUSLY, the major­i­ty of the bank tellers of the world are feminists?

    This is your argu­ment to say that peo­ple are not stu­pid, it was just con­fus­ing language?

  10. Paul Dundon says

    July 10, 2008 at 5:28

    The claim that Lin­da is more like­ly to be a banker than a banker and a fem­i­nist is just unsub­stan­ti­at­ed. Pri­ma facie, an indi­vid­ual is more like­ly to be a mem­ber of a larg­er group than a small­er one, but that isn’t the judge­ment we are being asked to make. We’re giv­en quite a lot of infor­ma­tion about Lin­da’s polit­i­cal views and asked to decide whether she is an active feminist.

    It’s more like­ly, pri­ma facie, that I’m Amer­i­can than it is that I’m British, because there are more Amer­i­cans than there are British. But if I say I live in the UK, think the Queen is great and call French Fries “chips” you would be fool­ish to say it was­n’t more like­ly I was British, despite the pri­or like­li­hood. In the same way, the fact that there are few­er fem­i­nist bankers than bankers is sim­ply not the issue in Lin­da’s case.

  11. Alvaro says

    July 11, 2008 at 6:54

    Paul, it´s not me dis­agree­ing with you, it is mathematics/ prob­a­bil­i­ty 101. As dis­cussed above, we may be mis­led by lan­guage and our auto­mat­ic assump­tions, but that is pre­cise­ly why this lit­tle teas­er is eye-opening.

    Once we are told that she is a banker, the prob­a­bil­i­ty of her being a banker: 100%

    Prob­a­bil­i­ty she is, adit­tion­al­ly, active in the fem­i­nist move­ment: you pick. Per­haps 10%? 80%? in any case, it will be less than 100%, oth­er­wise you are assum­ing it is impos­si­ble that she may have cho­sen not to be active in the fem­i­nist movement.

  12. Andy Manjuck says

    July 13, 2008 at 1:02

    Per­haps peo­ple tak­ing the sur­vey asso­ci­at­ed the idea of fem­i­nism with being quizzed on being a “pro­gres­sive” thinker and caught onto it like a buzz word. No longer does it become a ques­tion of AND/OR log­ic… no it just becomes a cul­ture quite aware of how often it’s test­ing its ever-chang­ing view on the eth­i­cal nature of the world.

  13. Richard McLaughlin says

    August 10, 2008 at 10:46

    I thought dif­fer­ent from oth­ers, why would a bank teller and be active in the fem­i­nist move­ment. Does one exclude the other.

    David Osborne prob­a­bly described it best for me.

  14. dwindle says

    August 14, 2008 at 9:34

    I remem­ber one about a small old­er man who likes poet­ry and clas­si­cal piano. Ivy League pro­fes­sor or truck dri­ver? Well, obvi­ous­ly a truck dri­ver, because they out­num­ber Ivy League pro­fes­sor sev­er­al times over.

  15. Alvaro says

    August 15, 2008 at 7:49

    dwin­dle, not a very accu­rate analogy…

    Do you think he’d more like­ly be a truck dri­ver, or a truck dri­ver who lis­tens to Mozart all the time while men­tal­ly com­pos­ing haikus?

    or,

    Do you think he’d be more like­ly to be an Ivy League pro­fes­sor, or an Ivy League pro­fes­sor who attends clas­si­cal music per­for­mances every week?

  16. Flo says

    August 20, 2008 at 12:57

    The answer is (a). Lin­da is a bank teller “today”. She was an activist when she was a stu­dent. Do I know if she is still an activist today? Nope.

  17. PJ says

    March 21, 2009 at 6:31

    The answers very sim­ple, it’s not that you’re “dumb”, it’s that peo­ple flip through sites like this one because theyre not worth think­ing about. The inter­net is for enter­tain­ment, not for show­ing oth­ers the “ha ha boohoo” of how you fell for their lit­tle twist.

    If the options were reverse (A. Lin­da is a fem­i­nist, and B. Lin­da is a fem­i­nist AND a banker) then most peo­ple would have cho­sen A. I guar­an­tee it

  18. Cassady says

    October 22, 2009 at 3:15

    I think what is more inter­est­ing is that peo­ple thought “Lin­da” ambi­tious enough to be both a full time banker and fem­i­nist. I love it!

Primary Sidebar

Top Articles on Brain Health and Neuroplasticity

  1. Can you grow your hippocampus? Yes. Here’s how, and why it matters
  2. How learning changes your brain
  3. To harness neuroplasticity, start with enthusiasm
  4. Three ways to protect your mental health during –and after– COVID-19
  5. Why you turn down the radio when you're lost
  6. Solving the Brain Fitness Puzzle Is the Key to Self-Empowered Aging
  7. Ten neu­rotech­nolo­gies about to trans­form brain enhance­ment & health
  8. Five reasons the future of brain enhancement is digital, pervasive and (hopefully) bright
  9. What Educators and Parents Should Know About Neuroplasticity and Dance
  10. The Ten Habits of Highly Effective Brains
  11. Six tips to build resilience and prevent brain-damaging stress
  12. Can brain training work? Yes, if it meets these 5 conditions
  13. What are cognitive abilities and how to boost them?
  14. Eight Tips To Remember What You Read
  15. Twenty Must-Know Facts to Harness Neuroplasticity and Improve Brain Health

Top 10 Brain Teasers and Illusions

  1. You think you know the colors? Try the Stroop Test
  2. Check out this brief attention experiment
  3. Test your stress level
  4. Guess: Are there more brain connections or leaves in the Amazon?
  5. Quick brain teasers to flex two key men­tal mus­cles
  6. Count the Fs in this sentence
  7. Can you iden­tify Apple’s logo?
  8. Ten classic optical illu­sions to trick your mind
  9. What do you see?
  10. Fun Mental Rotation challenge
  • Check our Top 25 Brain Teasers, Games and Illusions

Join 12,559 readers exploring, at no cost, the latest in neuroplasticity and brain health.

By subscribing you agree to receive our free, monthly eNewsletter. We don't rent or sell emails collected, and you may unsubscribe at any time.

IMPORTANT: Please check your inbox or spam folder in a couple minutes and confirm your subscription.

Get In Touch!

Contact Us

660 4th Street, Suite 205,
San Francisco, CA 94107 USA

About Us

SharpBrains is an independent market research firm tracking health and performance applications of brain science. We prepare general and tailored market reports, publish consumer guides, produce an annual global and virtual conference, and provide strategic advisory services.

© 2023 SharpBrains. All Rights Reserved - Privacy Policy