The Psychology of Biases


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Are you convinced that test-driven development (TDD) will benefit your team, but you find some developers view the practice as unproductive and unhelpful? Are you the lone voice advocating for continuous integration (CI), really convinced it will bring huge benefits, but others don't want to listen? Do you see the wisdom of secure-by-design and actively assessing software security, yet management feels that they've avoided any problems so far and assume they'll continue to avoid problems.

Research tells us that the information we take in depends on a person’s assumptions, aversions, biases, and preconceptions. Broadly speaking, psychologists and scientists call these cognitive biases. People who study organizational behavior use their understanding of cognitive biases to bring important improvements and change to individuals, teams, and organizations.

Come learn about common cognitive biases that impact development teams. Let's explore strategies to identify and cope with seemingly irrational decisions against new and better practices. Through specific examples, learn some straightforward ways that may help you manage the opposition you encounter that can hold teams back.

Stephen Ritchie is the author of Pro .NET Best Practices ( and the organizer of the DC ALT .NET group ( He has been writing software professionally for over 20 years. Stephen works as a software development consultant at Excella Consulting in the Washington, D.C. area. His passion for following best practices has taught him to appreciate the value of experience, practical know-how, and continuous learning. Stephen is the .NET best practices steward at Excella Consulting, working with .NET project teams to facilitate and sort out the helpful practices from the unhelpful ones, the practicable from the impracticable, and the "sounds good" from the "it really is good" practices and principles.

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  • Tonight I’m going to:-- Describe the Semmelweis Reflex-- And explain to you how it might impact you,-- And also, show you some ways to cope with it,-- Hopefully, you’ll learn how to avoid it.
  • First, let’s meet Dr. SemmelweisHe was a young physician, delivering babies in Austria, some one hundred and fifty years ago
  • At that time, the maternity wards were ravaged by a disease, which was known as childbed fever
  • Some 30% of the patients died from this disease
  • Nearby, another maternity ward had much lower rates
  • Dr. Semmelweis wanted to understand the difference.He decided to apply the scientific method
  • His educatedguess was:After you perform an autopsy …
  • And, before you deliver a baby …
  • Scrub your hands.This seems to prevent the spread of the disease.
  • His experiments worked!Again.And Again.
  • Semmelweis drew a startling conclusion.Physicians were transmitting this disease.
  • You can just imagine the headlines in those days.
  • Sadly, very few people know anything about Dr. Semmelweis.But why not?
  • He did the unthinkable.He contradicted established beliefs.
  • First, blood is one of the 4 humours. -- Disease is transmitted by bad smells.Second, the Hippocratic Oath. -- Doctors do not harm their patients.
  • So, how did his fellow physicians react to Dr. Semmelweis?With Contempt
  • Let’s define the Semmelweis Reflex:A tendency to reject new evidence or new knowledge because it contradicts Established wisdom, beliefs, or understanding.Okay. How is any of this relevant to you?
  • As a consultant, you may find yourself challenging conventional wisdom.For example, agile makes some BOLD assertions:
  • Focus on getting people to work well together.Less process
  • And some things you do …Make things worse!
  • You’ve got to STOP being right all the time.
  • Here are some things to focus on.Work with the client …Focusing on these thingshelp you cope with the reflex.Or avoid it in the first place.
  • Be more like Dr. McDreamy.Have a great bedside manner.
  • So, whatever happened to Dr. Semmelweis.-- He turned every conversation to the topic of childbed fever-- Worse! He insisted that all instances of the disease could be traced back to only one single cause: a doctor’s lack of cleanliness-- Many were offended by his conclusion.-- Confident that he knew how to prevent death, he was extremely disturbed by all the needless human suffering.-- He became severely depressed
  • He was lured to this insane asylum.
  • He was put in a straightjacket, beaten, and died two weeks later …At the age of 47.
  • Today, he is not forgotten.After all, he was right all along.
  • If you don’t want to end up like Dr. Semmelweis,Don’t be an ass.
  • Now you know what the Semmelweis Reflex is all about.It is a negativereaction to unconventional wisdom.You will encounter it because you bring new/original thoughts and ideas to the table.You cope with it by not attacking; possess inner strengthYou overcome it by being patient; remain playful, remain calm.
  • Here are some things to focus on.
  • Here are some things to focus on.
  • Here are some things to focus on.
  • The Psychology of Biases

    1. 1. The Psychology of Biases Why Some Folks Are Averse to Better Development Practices Stephen Ritchie 15-Apr-2014
    2. 2. Excella Consulting Warm Up • Three Clues –Handouts –Two Secret Clues –Third Clue in the Slides
    3. 3. Excella Consulting Warm Up • Third clue: – One word answer – Begins with “H” – Ends with “y” • Once the question is asked, quickly write down your one word answer. • Stand up once you have the answer.
    4. 4. Excella Consulting Warm Up What one word best describes how she was feeling just before Mary had a little lamb?
    5. 5. Excella Consulting Warm Up What are your answers? Happy Hungry Hostility
    6. 6. Excella Consulting Definition Cognitive Bias Own “subjective reality” from their perception of input
    7. 7. Excella Consulting Personal Story
    8. 8. Excella Consulting Personal Story
    9. 9. Excella Consulting Cognitive Bias Semmelweis Reflex
    10. 10. Excella Consulting Meet the man … Dr. Semmelweis, M.D. Obstetrician Young Vienna 1846
    11. 11. Excella Consulting Problem: Childbed Fever
    12. 12. Excella Consulting Mother’s Mortality Rate Up To 30% Semmelweis’ Hospital
    13. 13. Excella Consulting Mother’s Morality Rate More Moderate 7.5% Neighboring Hospital
    14. 14. Excella Consulting Scientific Method Q: Why the difference? Hypothesis Experiment Conclusion
    15. 15. Excella Consulting Hypothesis Between the morgue…
    16. 16. Excella Consulting Hypothesis And the delivery room…
    17. 17. Excella Consulting Hypothesis Disinfect!
    18. 18. Excella Consulting Mother’s Mortality Rate Mortality Rate Dropped Under 1% Semmelweis’ Results
    19. 19. Excella Consulting Conclusion Lack of Cleanliness Caused Death
    20. 20. Excella Consulting Headline 1847: Physician Makes Amazing Discovery Easy to implement, easily proven, and clearly saves lives.
    21. 21. Excella Consulting Why has nobody ever heard of him? Dr. Semmelweis, M.D. Who? Semmel
    22. 22. Excella Consulting Semmelweis’ Approach Conventional Wisdom Challenged
    23. 23. Excella Consulting Contemporaries’ Beliefs Hippocrates4 Humours
    24. 24. Excella Consulting Reaction Rejection Criticism Scorn
    25. 25. Excella Consulting Definition Semmelweis Reflex Reject new evidence that contradicts established beliefs
    26. 26. Excella Consulting Preaching Heresy
    27. 27. Excella Consulting Test-Driven Development Test CodeRefactor
    28. 28. Excella Consulting Confound Your Logic, Mr. Spock! Logical Sequential Rational Analytical
    29. 29. Excella Consulting No Silver Bullet Fault Defect Wrong Solution Avoid
    30. 30. Excella Consulting Focus On The Pain Pain Points Adaptations Experiments Results Outcomes
    31. 31. Excella Consulting Doctor McDreamy Understanding Gentle Helpful Intuitive Patient
    32. 32. Excella Consulting Epilogue So, whatever became of Dr. Semmelweis?
    33. 33. Excella Consulting Lured To An Asylum …
    34. 34. Excella Consulting Put in a straightjacket …
    35. 35. Excella Consulting Honored Posthumously
    36. 36. Excella Consulting Don’t Be Like Semmelweis Insistence Avoid: Obsession Arrogance
    37. 37. Excella Consulting Relax, Have Fun Wit It
    38. 38. Excella Consulting Cognitive Bias Normalcy Bias
    39. 39. Excella Consulting Tornado Alley
    40. 40. Excella Consulting How many tornado shelters in “Tornado Alley”? Oklahoma Percentage of homes with storm shelters?
    41. 41. Excella Consulting Surprisingly In the Oklahoma City area, perhaps 10 to 20 percent of homes have some kind of formal shelter. Most houses and public buildings in ‘Tornado Alley’ lack storm shelters, by Agence France-Presse. May 22, 2013
    42. 42. Excella Consulting Surprisingly “Unfortunately, people prefer homes with swimming pools rather than storm shelters,” said Oklahoma State Representative Joe Dorman Most houses and public buildings in ‘Tornado Alley’ lack storm shelters, by Agence France-Presse. May 22, 2013
    43. 43. Excella Consulting Definition Normalcy Bias Underestimate both the possibility and effects of a disaster
    44. 44. Excella Consulting With a name like Target, are we surprised?
    45. 45. Excella Consulting Security Development Lifecycle Security & Privacy Risk Assessments Static Analysis Incident Response Fuzz Testing
    46. 46. Excella Consulting SDL Implementation
    47. 47. Excella Consulting Six Sigma
    48. 48. Excella Consulting Cognitive Bias Ambiguity Effect
    49. 49. Excella Consulting OCR
    50. 50. Excella Consulting Punch Card
    51. 51. Excella Consulting Tried and True “… it would be excessively costly to IBM to quickly introduce more modern machinery using electronics and magnetic tape instead of relays and punched cards.” From Tabulators to Early Computers in the U.S. Life Insurance Industry: Co-evolution and Continuities, JoAnne Yates, October 1993, CCS WP #153, Sloan School WP #3618-93
    52. 52. Excella Consulting Definition Ambiguity Effect Favor an option where the outcome is known over one where the outcome is unknown
    53. 53. Excella Consulting Exercise • On your index card • Write 3 specific examples • Organizations pick development patterns and practices that are – “old and adequate” over “new and better” – “tried and true” over “possibly better” – “always done it” over “unprecedented”
    54. 54. Excella Consulting Why did we decide to go with … Automated Testing Manual Testing over
    55. 55. Excella Consulting Why did we decide to go with … Automated Builds Manual Builds over
    56. 56. Excella Consulting Why did we decide to go with … Scripts Manual Configuration over
    57. 57. Excella Consulting Why did we decide to go with … Continuous Integration Final Integration over
    58. 58. Excella Consulting Knowledge, Skill, and Attitude What to do Barriers How to do it Why to do it
    59. 59. Excella Consulting Training, Coaching, and Practice Short tutorial Trial period Training course Measure value Embed a coach
    60. 60. Excella Consulting Cognitive Bias Dunning- Kruger Effect
    61. 61. Excella Consulting Definition Dunning-Kruger Effect Some people can wildly overestimate their relative competence
    62. 62. Excella Consulting I want to be a lion tamer! Monty Python - Vocational Guidance Counselor sketch
    63. 63. Excella Consulting Definition Dunning-Kruger Effect People with true ability can tend to underestimate their relative competence
    64. 64. Excella Consulting Let’s switch to NoSQL
    65. 65. Excella Consulting Uninitiated Easy concept Inflated experts Not yet challenged Lack experience
    66. 66. Excella Consulting Knowledge Transfer, Experience, and Expertise Patience & wisdom Proof-of-concept Knowledge transfer Know-how Experience
    67. 67. Excella Consulting We are all individuals. (I’m not!) “In a very real sense there is no such thing as organizational behavior. There is only individual behavior. Everything else flows out of that.” Principle-Centered Leadership, Stephen Covey
    68. 68. Excella Consulting • Stephen Ritchie • Excella Consulting – .NET developer – “Best Practices” – Training agile eng – ScrumMaster/coach • • tchie • @ruthlesshelp • Organizer DC Alt.NET Shameless Self Promotion
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