Cognitive biases
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Cognitive biases

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A quick introduction to the fascinating area of cognitive biases. Be sure to check out the slide notes for more information.

A quick introduction to the fascinating area of cognitive biases. Be sure to check out the slide notes for more information.

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  • What are cognitive biases?Most people think they behave rationallyIt turns out that people are susceptible to limitations in thinking, judgement and decision makingStems from several areas of cognitionMemoryPerceptionFeelingsMisapplication of statistical reasoningIntroduced in 1972 by Amos Tversky and Daniel KahnmanThe list of identified cognitive biases runs into the hundreds
  • Where do the biases come from?At some point in our evolutionary history these biases were useful adaptationsMostly they help make decisions with limited informationUseful if your only task for the day is survival, and speed of decision is more important that accuracyHowever in today’s world the opposite is trueNow we need to do more than just survive they can get us into troubleParts of our lives and society rely on sound decisionsFinding a partnerMaking a purchaseJuries!!!
  • Some examples – Confirmation BiasWe like things that match our view of the worldTo the extent that we search out things that agree with us, whilst ignoring conflicting informationIt is a short circuit to keeping away from things that may cause us harmBut…Makes it difficult to let go of entrenched positionsMakes people open to scams such as psychic readingsThe uncomfortable feeling of anxiety we get when the real world does not fit in with out world view is called cognitive dissonance.
  • Fundamental attribution errorA quirk in the way we reason about causalityAttributing an aspect of a persons behaviour to their fundamental character rather than the situation If I loose my keys I am just unlucky, if someone else looses their keys they are carelessWhat other examples are there?
  • FramingPeople react differently to a choice depending on how the information is framedLoss versus gainPositive versus negativeIs it better to say a medical intervention has 90% chance of success or a 10% chance of death?It depends on what you desire as an outcomeThis bias is the cornerstone of marketing and political spin
  • AnchoringHumans tend to rely on the first piece of information offered when making decisions. This is the anchor.Subsequent decisions are made by adjusting away from the anchorSo in negotiations the first price offered sets the anchorRelated to a similar effect called priming
  • Illusionary SuperiorityPeople tend to overestimate their positive qualities relative to other people or groupsThis is widespread in all aspects of lifeIntelligence, sporting ability, academic performance, job performance, popularity, confidence, …We even struggle to understand that in most cases it is a nonsensical premiseEven at Cambridge around half of the students academic abilities are below average for their cohortThis is linked to the Dunning-Kruger effect
  • Survivorship BiasIt is easy to see the things that survived – they are all around usWe often overlook the things that didn’t because they are not visibleCould be actual people – medical trails not taking into account the people that dropped outFocusing on what leading businesses / business leaders did rather than understanding what the countless other who failed did or did not doThe bomber problem was real issue faced during WWII http://youarenotsosmart.com/2013/05/23/survivorship-bias/
  • Sammelweis ReflexThis is the dismissal of new evidence because it does not comply with the established norms of the dayNamed after Ignaz Sammelweis, who found a causal link between childbed fever and the mortality rates of new mothersDemonstrated washing hands could reduce death ratesIgnored by his peers as he could find no acceptable scientific explanation and his contemporaries simple refused to believe himDoes this happen a lot in IT?
  • Regression to the meanNot exactly a cognitive bias, but a similar failure in statistical reasoningIf a variable is extreme in the first measurement, it will tend to be closer to the average for the second measurementGives rise to the idea that punishment is effectiveIf someone performs badly and is punished it is more likely that the next time their performance will be closer to the averageLikewise with praise
  • So now we know about them we are ok?

Cognitive biases Cognitive biases Presentation Transcript

  • COGNITIVE BIASES
  • What are cognitive biases? • Most people think they behave rationally • It turns out that people are susceptible to limitations in thinking, judgement and decision making • Stems from several areas of cognition • Memory • Perception • Feelings • Misapplication of statistical reasoning • … • Introduced in 1972 by Amos Tversky and Daniel Kahneman • The list of identified cognitive biases runs into the hundreds
  • Where do the biases come from? • At some point in our evolutionary history these biases were useful adaptations • Mostly they help make decisions with limited information • Useful if your only task for the day is survival, and speed of decision is more important that accuracy • However in today’s world the opposite is true • Now we need to do more than just survive they can get us into trouble • Parts of our lives and society rely on sound decisions • Finding a partner • Making a purchase • Juries!!! • …
  • Some examples – Confirmation Bias • We like things that match our view of the world • To the extent that we search out things that agree with us, whilst ignoring conflicting information • It is a short circuit to keeping away from things that may cause us harm • But… • Makes it difficult to let go of entrenched positions • Makes people open to scams such as psychic readings • The uncomfortable feeling of anxiety we get when the real world does not fit in with out world view is called cognitive dissonance.
  • Fundamental attribution error • A quirk in the way we reason about causality • Attributing an aspect of a persons behaviour to their fundamental character rather than the situation • If I loose my keys I am just unlucky, if someone else looses their keys they are careless • What other examples are there?
  • Framing • People react differently to a choice depending on how the information is framed • Loss versus gain • Positive versus negative • Is it better to say a medical intervention has 90% chance of success or a 10% chance of death? • It depends on what you desire as an outcome • This bias is the cornerstone of marketing and political spin
  • Anchoring • Humans tend to rely on the first piece of information offered when making decisions. This is the anchor. • Subsequent decisions are made by adjusting away from the anchor • So in negotiations the first price offered sets the anchor • Related to a similar effect called priming
  • Illusionary Superiority • People tend to overestimate their positive qualities relative to other people or groups • This is widespread in all aspects of life • Intelligence, sporting ability, academic performance, job performance, popularity, confidence, … • We even struggle to understand that in most cases it is a nonsensical premise • Even at Cambridge around half of the students academic abilities are below average for their cohort • This is linked to the Dunning-Kruger effect
  • Survivorship Bias • It is easy to see the things that survived – they are all around us • We often overlook the things that didn’t because they are not visible • Could be actual people – medical trails not taking into account the people that dropped out • Focusing on what leading businesses / business leaders did rather than understanding what the countless other who failed did or did not do • This bias was faced for real during WWII when investigating the cause of bomber losses
  • Sammelweis Reflex • This is the dismissal of new evidence because it does not comply with the established norms of the day • Named after Ignaz Sammelweis, who found a causal link between childbed fever and the mortality rates of new mothers • Demonstrated washing hands could reduce death rates • Ignored by his peers as he could find no acceptable scientific explanation and his contemporaries simple refused to believe him • Does this happen a lot in IT?
  • Regression to the mean • Not exactly a cognitive bias, but a similar failure in statistical reasoning • If a variable is extreme in the first measurement, it will tend to be closer to the average for the second measurement • Gives rise to the idea that punishment is effective • If someone performs badly and is punished it is more likely that the next time their performance will be closer to the average • Likewise with praise
  • So now we know about them we are ok? • Well, not so much • Knowing about them does not mean that you will be able to spot them all the time. It does help. • If a decision is important you must explicitly call out the biases to make sure you are not being tricked
  • Further reading • Wikipedia’s list of cognitive biases http://en.wikipedia.org/wiki/List_of_cognitive_biases • Thinking Fast and Slow – Daniel Kahneman http://www.amazon.co.uk/Thinking-Fast-Slow-Daniel- Kahneman/dp/0141033576/ • Bad science – Ben Goldacre http://www.amazon.co.uk/Bad-Science-Ben- Goldacre/dp/000728487X/ • Loads more…