Linda is 31 years old, single, outspoken, and very bright. As a student, she was deeply concerned with issues of discrimin...
Linda is 31 years old, single, outspoken, and very bright. As a student, she was deeply concerned with issues of discrimin...
Conjunction fallacy <ul><li>IF  Pr (Linda is a bank teller)  = 0.10  AND  Pr (Linda is a feminist)  = 0.95… </li></ul><ul>...
<ul><li>A 55-year-old woman had pulmonary embolism documented angiographically 10 days after cholecystectomy . </li></ul><...
More probable Less probable 37 medical postgrads at Harvard University  plus 66 internists at New England Medical Center 3...
Difficulties with probabilistic reasoning Tossing one coin, what is the chance of it landing on “Heads”? A: 0.50  (or, in ...
Difficulties with probabilistic reasoning Tossing two coins, what is the chance of getting two “Heads”? A:   0.25   (or, i...
Difficulties with probabilistic reasoning If a test to detect a disease whose prevalence is 1/1000 has a false positive ra...
Difficulties with probabilistic reasoning 999/1000 x .05 Cited by Pinker (1997) <ul><li>[Base-rate]   x  [Test sensitivity...
Difficulties with probabilistic reasoning ) ] + ( 0.001 0.04995 0.001 1.0 Cited by Pinker (1997) <ul><li>[Base-rate]   x  ...
Difficulties with probabilistic reasoning <ul><li>Among Staff and Students of Harvard Medical School ( n  = 60): </li></ul...
Difficulties with probabilistic reasoning Gøtzsche PC, Nielsen M. Screening for breast cancer with mammography.  Cochrane ...
 
<ul><li>Where mental shortcuts systematically undermine our judgement of  probabilities </li></ul><ul><ul><li>May explain ...
There are also some economic principles involved...
But… Are cognitive errors really  sufficient  to account for false beliefs?
http://www.gallup.com/poll/19558/Paranormal-Beliefs-Come-SuperNaturally-Some.aspx
http://www.gallup.com/poll/19558/Paranormal-Beliefs-Come-SuperNaturally-Some.aspx
 
http://www.gallup.com/poll/27847/Majority-Republicans-Doubt-Theory-Evolution.aspx
Maybe… … our brains are  pre-programmed  to find false beliefs  attractive
Tendency toward non-empirical beliefs may be physiologically in-built
Non-empirical beliefs may promote inclusive fitness Sosis, R. (2000). Religion and intragroup cooperation: Preliminary res...
Non-empirical thinking may serve as a “costly signal” of individual fitness Sosis, R., & Bressler, E. (2003). Cooperation ...
Faulty beliefs may boost one’s self-esteem Data from 1,000,000 students Cited by Gilovich (1991)
Faulty beliefs may boost one’s self-esteem Data from 1,000,000 students Cited by Gilovich (1991) Self-rated &quot;Ability ...
Faulty beliefs may boost one’s self-esteem Data from 1,000,000 students Cited by Gilovich (1991) “ Top 1%” 25% “ Also in t...
Faulty beliefs may boost one’s self-esteem Data from university lecturers Cited by Gilovich (1991)
Faulty beliefs may boost one’s self-esteem Everyone All-round greatness “ Me!”
<ul><li>Common illusions </li></ul><ul><li>Unrealistically positive self-regard </li></ul><ul><li>Illusions of control </l...
Depression, confidence, and accuracy Szu-Ting Fu, T., Koutstaal, W., Poon, L., & Cleare, A. J. (2012). Confidence judgment...
Szu-Ting Fu, T., Koutstaal, W., Poon, L., & Cleare, A. J. (2012). Confidence judgment in depression and dysphoria: The dep...
Szu-Ting Fu, T., Koutstaal, W., Poon, L., & Cleare, A. J. (2012). Confidence judgment in depression and dysphoria: The dep...
Too much of a bad thing Soderstrom, N. C., Davalos, D. B., & Vázquez, S. M. (2011). Metacognition and depressive realism: ...
<ul><li>If faulty thinking in non-depression ‘protects’ people who are  not  depressed… </li></ul><ul><li>… does accurate ...
http://www.pharmacytechs.net/blog/old-school-medicine-ads
http://www.pharmacytechs.net/blog/old-school-medicine-ads
http://www.pharmacytechs.net/blog/old-school-medicine-ads
http://www.pharmacytechs.net/blog/old-school-medicine-ads
http://www.pharmacytechs.net/blog/old-school-medicine-ads
http://slowmoodmovement.wordpress.com/2011/05/29/the-rise-of-the-brain-self/
http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
The “Third-Person Effect” Davison, W. P. (1983). The Third-Person Effect in communication.  Public Opinion Quarterly ,  47...
Impact of depression on Third Person Effect,  for anti-depressant advertisements Taylor, L. D., Bell, R. A., & Kravitz, R....
A tendency to make mistakes appears to be an   evolved , adaptive mechanism in mentally healthy people Meanwhile,  accurat...
 
Two Final Questions 1. Can faulty thinking be neutralized?  2. Should   faulty thinking be neutralized?
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Lecture given at Cork Skeptics, 26 November 2011. See http://thesciencebit.net

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  • Groups: 32, 20, 16 Selling point: actual DSM-IV clinical patients (CFS = dysphoria) Separated depressive realism vs. negativity by looking at during vs after
  • Groups: 58, 20, 19 (men and women college students) Selling point: moderate depression using clinical tool, screened from c. 350
  • Sample: 148 adults (mostly women) with depression for a year or more, and taking meds Very depressed – more accurate, more sceptical, more protected
  • Slideshare cork skep3

    1. 2. Linda is 31 years old, single, outspoken, and very bright. As a student, she was deeply concerned with issues of discrimination and social justice . Which of the following is most likely: (a) Linda is a bank teller (b) Linda is a bank teller and is active in the feminist movement
    2. 3. Linda is 31 years old, single, outspoken, and very bright. As a student, she was deeply concerned with issues of discrimination and social justice . Which of the following is most likely: (a) Linda is a bank teller (b) Linda is a bank teller and is active in the feminist movement
    3. 4. Conjunction fallacy <ul><li>IF Pr (Linda is a bank teller) = 0.10 AND Pr (Linda is a feminist) = 0.95… </li></ul><ul><li>THEN Pr (Linda is a bank teller and a feminist) = 0.10 × 0.95 </li></ul><ul><li>= or 0.095 </li></ul><ul><li>i.e., lower than Pr (Linda is a bank teller) </li></ul>Based on http://paradigmsanddemographics.blogspot.com/2011/09/logical-fallacy-of-week-conjunction.html
    4. 5. <ul><li>A 55-year-old woman had pulmonary embolism documented angiographically 10 days after cholecystectomy . </li></ul><ul><li>Rate the likelihood of the following subsequent after-effects: </li></ul><ul><ul><li>The woman experienced pleuritic chest pain </li></ul></ul><ul><ul><li>The woman experienced dyspnea and hemiparesis </li></ul></ul><ul><ul><li>The woman experienced hemiparesis </li></ul></ul><ul><ul><li>The woman experienced hemoptysis </li></ul></ul><ul><ul><li>etc. </li></ul></ul>
    5. 6. More probable Less probable 37 medical postgrads at Harvard University plus 66 internists at New England Medical Center 32 physicians at Stanford University Tversky & Kahneman (1983)
    6. 7. Difficulties with probabilistic reasoning Tossing one coin, what is the chance of it landing on “Heads”? A: 0.50 (or, in other words, a fifty-fifty chance) Throwing one dice, what is the chance of it landing on “5”? A: 0.17 (or, in other words, a one-in-six chance)
    7. 8. Difficulties with probabilistic reasoning Tossing two coins, what is the chance of getting two “Heads”? A: 0.25 (or, in other words, a 1-in-4 chance) Throwing two dice, what is the chance of getting two “5”s? A: 0.028 (or, in other words, a 1-in-36 chance)
    8. 9. Difficulties with probabilistic reasoning If a test to detect a disease whose prevalence is 1/1000 has a false positive rate of 5%, what is the chance that a person found to have a positive result actually has the disease, assuming you know nothing about the person’s symptoms or signs? Cited by Pinker (1997) <ul><li>Among Staff and Students of Harvard Medical School ( n = 60): </li></ul><ul><li>Most popular answer = 0.95 (i.e., a 19 out of 20 chance) </li></ul><ul><li>Average of all answers = 0.56 (c., a fifty-fifty chance) </li></ul>
    9. 10. Difficulties with probabilistic reasoning 999/1000 x .05 Cited by Pinker (1997) <ul><li>[Base-rate] x [Test sensitivity] / [Rate of positive results] </li></ul>[ 1/1000 ] Prevalence of disease per 1000 [ 1/1 ] Proportion of sick who test positive Number of positive results per 1000 1/1000 + ( [ )] “ False positives” i.e., well persons who test ‘positive’ If a test to detect a disease whose prevalence is 1/1000 has a false positive rate of 5%, what is the chance that a person found to have a positive result actually has the disease, assuming you know nothing about the person’s symptoms or signs? Actual sick persons testing ‘positive’
    10. 11. Difficulties with probabilistic reasoning ) ] + ( 0.001 0.04995 0.001 1.0 Cited by Pinker (1997) <ul><li>[Base-rate] x [Test sensitivity] / [Rate of positive results] </li></ul>= 0.019627 [ x / = = 0.001 / 0.05095 ≈ 0.02 If a test to detect a disease whose prevalence is 1/1000 has a false positive rate of 5%, what is the chance that a person found to have a positive result actually has the disease, assuming you know nothing about the person’s symptoms or signs?
    11. 12. Difficulties with probabilistic reasoning <ul><li>Among Staff and Students of Harvard Medical School ( n = 60): </li></ul><ul><li>Most popular answer </li></ul><ul><li>= 0.95 (i.e., a 19 out of 20 chance) </li></ul><ul><li>Average of all answers </li></ul><ul><li>= 0.56 (c., a fifty-fifty chance) </li></ul>Cited by Pinker (1997) ≈ 0.02 (or, in other words, a 1-in-50 chance) If a test to detect a disease whose prevalence is 1/1000 has a false positive rate of 5%, what is the chance that a person found to have a positive result actually has the disease, assuming you know nothing about the person’s symptoms or signs?
    12. 13. Difficulties with probabilistic reasoning Gøtzsche PC, Nielsen M. Screening for breast cancer with mammography. Cochrane Database of Systematic Reviews 2006, Issue 4. Art. No.: CD001877. DOI: 10.1002/14651858.CD001877.pub2 … For every 2000 women invited for screening throughout 10 years, one will have her life prolonged. In addition, 10 healthy women, who would not have been diagnosed if there had not been screening, will be [erroneously] diagnosed and treated unnecessarily…
    13. 15. <ul><li>Where mental shortcuts systematically undermine our judgement of probabilities </li></ul><ul><ul><li>May explain why rare events are seen as common, common events seen as rare, etc. </li></ul></ul>Cognitive Heuristics
    14. 16. There are also some economic principles involved...
    15. 17. But… Are cognitive errors really sufficient to account for false beliefs?
    16. 18. http://www.gallup.com/poll/19558/Paranormal-Beliefs-Come-SuperNaturally-Some.aspx
    17. 19. http://www.gallup.com/poll/19558/Paranormal-Beliefs-Come-SuperNaturally-Some.aspx
    18. 21. http://www.gallup.com/poll/27847/Majority-Republicans-Doubt-Theory-Evolution.aspx
    19. 22. Maybe… … our brains are pre-programmed to find false beliefs attractive
    20. 23. Tendency toward non-empirical beliefs may be physiologically in-built
    21. 24. Non-empirical beliefs may promote inclusive fitness Sosis, R. (2000). Religion and intragroup cooperation: Preliminary results of a comparative analysis of Utopian communities. Cross-Cultural Research , 34 , 70–87.
    22. 25. Non-empirical thinking may serve as a “costly signal” of individual fitness Sosis, R., & Bressler, E. (2003). Cooperation and commune longevity: A test of the costly signaling theory of religion. Cross-Cultural Research , 37 , 211–239.
    23. 26. Faulty beliefs may boost one’s self-esteem Data from 1,000,000 students Cited by Gilovich (1991)
    24. 27. Faulty beliefs may boost one’s self-esteem Data from 1,000,000 students Cited by Gilovich (1991) Self-rated &quot;Ability to get along with others&quot; Above average 100%
    25. 28. Faulty beliefs may boost one’s self-esteem Data from 1,000,000 students Cited by Gilovich (1991) “ Top 1%” 25% “ Also in top quarter” 35%
    26. 29. Faulty beliefs may boost one’s self-esteem Data from university lecturers Cited by Gilovich (1991)
    27. 30. Faulty beliefs may boost one’s self-esteem Everyone All-round greatness “ Me!”
    28. 31. <ul><li>Common illusions </li></ul><ul><li>Unrealistically positive self-regard </li></ul><ul><li>Illusions of control </li></ul><ul><li>Unrealistic optimism </li></ul>Faulty beliefs may be the brain’s default state <ul><li>Benefits </li></ul><ul><li>Happiness or contentment </li></ul><ul><li>Ability to care for others </li></ul><ul><li>Capacity for creativity/productivity </li></ul>
    29. 32. Depression, confidence, and accuracy Szu-Ting Fu, T., Koutstaal, W., Poon, L., & Cleare, A. J. (2012). Confidence judgment in depression and dysphoria: The depressive realism vs. negativity hypothesis. Journal of Behavior Therapy and Experimental Psychiatry , 43 , 699-704.
    30. 33. Szu-Ting Fu, T., Koutstaal, W., Poon, L., & Cleare, A. J. (2012). Confidence judgment in depression and dysphoria: The depressive realism vs. negativity hypothesis. Journal of Behavior Therapy and Experimental Psychiatry , 43 , 699-704.
    31. 34. Szu-Ting Fu, T., Koutstaal, W., Poon, L., & Cleare, A. J. (2012). Confidence judgment in depression and dysphoria: The depressive realism vs. negativity hypothesis. Journal of Behavior Therapy and Experimental Psychiatry , 43 , 699-704.
    32. 35. Too much of a bad thing Soderstrom, N. C., Davalos, D. B., & Vázquez, S. M. (2011). Metacognition and depressive realism: Evidence for the level-of-depression account. Cognitive Neuropsychiatry , 16 , 461-472.
    33. 36. <ul><li>If faulty thinking in non-depression ‘protects’ people who are not depressed… </li></ul><ul><li>… does accurate thinking in depression ‘protect’ people who are depressed? </li></ul>
    34. 37. http://www.pharmacytechs.net/blog/old-school-medicine-ads
    35. 38. http://www.pharmacytechs.net/blog/old-school-medicine-ads
    36. 39. http://www.pharmacytechs.net/blog/old-school-medicine-ads
    37. 40. http://www.pharmacytechs.net/blog/old-school-medicine-ads
    38. 41. http://www.pharmacytechs.net/blog/old-school-medicine-ads
    39. 42. http://slowmoodmovement.wordpress.com/2011/05/29/the-rise-of-the-brain-self/
    40. 43. http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
    41. 44. http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
    42. 45. http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
    43. 46. http://www.practiceofmadness.com/2010/03/psychiatric-drugs-a-history-in-ads/
    44. 47. The “Third-Person Effect” Davison, W. P. (1983). The Third-Person Effect in communication. Public Opinion Quarterly , 47 , 1-15. Self influenced by advertising Others influenced by advertising Quite a lot 32% 68% Some 24% 28% Not very much 20% 4% Not at all 16% 0% N/A 8% 0%
    45. 48. Impact of depression on Third Person Effect, for anti-depressant advertisements Taylor, L. D., Bell, R. A., & Kravitz, R. L. (2011). Third-person effects and direct-to-consumer advertisements for antidepressants. Depression and Anxiety , 28 , 160-165.
    46. 49. A tendency to make mistakes appears to be an evolved , adaptive mechanism in mentally healthy people Meanwhile, accurate thinking emerges in depression, perhaps also for adaptive reasons
    47. 51. Two Final Questions 1. Can faulty thinking be neutralized? 2. Should faulty thinking be neutralized?
    48. 52. http://thesciencebit.net

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