Why People Do NOT Believe Our Best Radiation Risk Estimates
A Presentation for the
Health Physics Society
Professional Development School on
Estimation of Radiological Risks
Purdue University, Lafayette IN
Friday, July 10, 2015
by
Ray Johnson, MS, PSE, PE, FHPS, CHP Director
Radiation Safety Counseling Institute 16440 Emory Lane
Rockville, MD 20853
[email protected] 301-370-8573
Why People Do NOT Believe Our Best Radiation Risk Estimates
HPS, Professional Development School, “Estimation of Radiological Risks”
Purdue University, Lafayette, IN, July 10, 2015
Ray Johnson, MS, PSE, PE, FHPS, CHJP Radiation Safety Counseling Institute
Rockville, MD [email protected]
Despite great care in developing our best radiation risk estimates, until these estimates are interpreted, they have no meaning, they are just numbers. After interpretation, the numbers mean whatever the interpreter believes. Thus, the interpretation or meaning of radiation risks can be highly subjective and variable. Specialists in radiation safety may find some common agreements on the meaning of radiation risk estimates because of similar understanding of the technology and basis for such estimates. Unfortunately, most of the world does not have that background and understanding and may interpret radiation risks very differently. Perhaps the primary basis for differences in understanding risk estimates is fear. Our minds are programmed for survival to be constantly alert to any evidence of risks. The media has done a good job over the past 70 years to instill fears of “Deadly Radiation” in virtually everyone. As soon as the word “radiation” comes up, fears follow automatically in the in the same way that people are instinctively afraid of snakes, heights, and immersion. People often equate radiation with cancer and death. They equate “risk” with “chance” and they are not willing to take a chance on getting cancer. Lacking a technical understanding of risk probabilities, when asked to evaluate a risk estimate, they may substitute a different question, such as, “How do I feel about getting cancer?” This is a question they can readily answer without any knowledge of radiation science or statistics. This approach eliminates any concerns for uncertainty or probabilities. Everyone knows of someone who has had cancer and they are aware of the awful consequences. The prospects of radiation causing cancer become an overwhelming influence on interpretation of risk estimates and decisions for radiation safety. Our natural human instincts for safety are not well suited to situations involving randomness or uncertainty. Thus, while people may not be certain about the risks of radiation effects, they are certain that they do not want to become a victim of cancer. Research has shown that, when chance is involved, peoples’ thought processes are often seriously flawed. When either information or understanding are lacking this invites competing interpretations. For many people there are no gradations, such a low risk or high risk. Rather there is “zero” risk or the outcome is a sure thing. Unfortunately, misunderstanding of risk estimates may have very negative consequences. This paper will look at how we evaluate risk and the processes that lead us to make poor decisions for radiation safety.
Raymond H. Johnson, MS, PSE, PE, FHPS, CHP Director, Radiation Safety Counseling Institute 301-370-8573 BS - Civil Engineering, University of Vermont (1961) MS - Sanitary Engineering, Massachusetts Institute of Technology (MIT) (1963) PSE - Professional Sanitary Engineer Degree, MIT and Harvard University (1963) PE – Licensed Professional Engineer, Vermont (1965 – present) PhD Studies, Radio and Nuclear Chemistry, Rensselaer Polytechnic Institute (1966–1972) Greater Washington Institute for Transactional Analysis – Counseling (1977–1980) CHP – Certified Health Physicist, American Board of Health Physics (1983–present) Johns Hopkins Fellow, Organizational Systems and Communications (1984–1985) FHPS - Fellow of the Health Physics Society and Past President (2000) Past President, American Academy of Health Physics (2015) Commissioned Stephen Minister – Counselor, United Methodist Church (2003–present)
Experience 2010 – pres. Director, Radiation Safety Counseling Institute. Workshops, training, and counseling for individuals,
companies, universities, or government agencies with concerns or questions about radiation and x-ray safety. Specialist in helping people understand radiation, what is safe, risk communication, worker counseling, psychology of radiation safety, and dealing with fears of radiation and nuclear terrorism for homeland security.
2007 – pres. VP, Training Programs and consultant to Dade Moeller Radiation Safety Academy, training and consulting in x-ray and radiation safety, safety program audits, radiation instruments, and regulatory requirements.
1984 - 2007 Director, Radiation Safety Academy. Providing x-ray and radiation safety training, audits, and consulting to industry (nuclear gauges and x-ray), universities, research facilities, and professional organizations.
1988 - 2006 Manager and Contractor to National Institutes of Health (NIH) for radiation safety audits of 3,500 research laboratories and 2,500 instrument calibrations a year, along with environmental monitoring, hot lab and analytic lab operations, and inspections of three accelerators and over 100 x-ray machines.
1990 - 2005 President of Key Technology, Inc. a manufacturer and primary laboratory for radon analysis with over 1,500,000 measurements since 1985. Primary instructor at Rutgers University for radon, radon measurements, radiation risks, radiation instruments, and radon risk communication courses (1990-1998).
1986 - 1988 Laboratory Director, RSO, Inc. Directed analytical programs and Quality Assurance for samples from NIH, Aberdeen Proving Ground, radiopharmaceutical companies, and the nuclear industry.
1970 - 1985 Chief, Radiation Surveillance Branch, EPA, Office of Radiation Programs. Directed studies of radiation exposures from all sources of radiation in the US, coordinated 7 Federal agencies for nuclear fallout events, QA officer 8 years. Head of US delegations to I.A.E.A and N.E.A. on radioactive waste disposal. ANSI N-13 delegate (1975-1985). Retired as PHS Commissioned Officer (0-6) in 1985 with 29 years of service.
1963 - 1970 U.S.P.H.S. Directed development of radiation monitoring techniques at DOE National Labs, nuclear plants, and shipyards in the US and Chalk River Nuclear Laboratory in Canada.
Health Physics and Professional Activities Health Physics Society (HPS) plenary member 1966; President-elect, President, Past President (1998-2001), Fellow (2000), Treasurer (1995-1998); Secretary (1992-1995); Executive Cmte. (1992-2001), Chair, Finance Cmte. (1996-1998); Head of U.S. delegation to IRPA X (2000). RSO Section Founder and Secretary/Treasurer (1997-2000); Co-founder and President, Radon Section (1995-1996). Co-Chair Local Arrangements Cmte. Annual Meeting in DC (1991); Public Info. Cmte. (1985-1988); Summer School Co-Chair (2004); Chair, President’s Emeritus, Cmte (2006); Chair, Awards Cmte. (2002); Chair, History Cmte. (2005-2012); Historian (2012-Pres.) Continuing Education Cmte. (2005-2012). Academic Dean for HPS Professional Development School on Radiation Risk Communication (2010) and Radiation Instruments School (2014). PEP, CEL and Journal Reviewer. AAHP Instructor; Treasurer, AAHP (2008 – 2011). AAHP President-elect, President, Past President (2012-2015). Baltimore-Washington Chapter: President (1990-1991) and Honorary Life Member; Newsletter Editor (1983-2005); Public Info. Chair (1983-1991), Science Teacher Workshop Leader (1995 – Pres.). New England Chapter HPS, Newsletter Editor, Board of Directors, Education Chair (1968-1972). President, American Association of Radon Scientists and Technologists (1995-1998) and Honorary Life Member, Charter Member; Board of Directors; Newsletter Editor (1990-1993). Founder and first President, National Radon Safety Board (NRSB) (1997-1999). Member of American Industrial Hygiene Association (1997-Pres.) (Secretary, Vice Chair, Chair, Ionizing Radiation Committee, 2009-2012), Conference of Radiation Control Program Directors (1997-Pres.), Studied H.P. communication styles and presented Myers-Briggs seminars to over 3500 H.P.s since 1984. Over 35 professional society awards. Licensed Professional Engineer since 1965. Certified Health Physicist since 1983.
Publications Authored over 500 book chapters, articles, professional papers, training manuals, technical reports, and presentations on radiation safety. Author of monthly column, “Insights in Communication” HPS Newsletter 1984 – 1989, 1994 -2001, and 2012- 2013. Contact at: 301-990-6006, [email protected]. 301-370-8573, www.radiationcounseling.org
Why People Do NOT Believe Our Best Radiation Risk Estimates
HPS, PDS, Purdue University, Lafayette, IN July 10, 2015 1
Why People Do NOT Believe Our Best Radiation Risk
Assessments
Ray Johnson, MS, PSE, PE, FHPS, CHPDirector
Radiation Safety Counseling [email protected]
Professional Development School
Radiation Risk AssessmentsHealth Physics Society
Purdue University
Lafayette, IN Friday, July 10, 2015
Outline for this PDS LectureMeaning of radiation risk assessments
Basis for evaluation of radiation risks
Radiation risks and fears
How we process data for assessing risks
How these processes areprone to errors
Effects of random chance
Why people interpret risks differentlyHPS PDS, Purdue University, July 10, 2015 2
My OdysseyI am not a specialist in radiation risk
assessment –– 50 years in radiation safety
I am not a specialist in psychology– 3 years of training in 1970s
to practice counseling
35 years of building links betweenpsychology and radiation safety
Trying to understand basis of radiation fears for better communication
HPS PDS, Purdue University, July 10, 2015 3
Credit for Inspiration
Richard Toohey, Ph.D., CHPPresident-Elect, HPS
“Why No One Believes Us:
Cognitive Neuroscience
and Radiation Risk”
HPS PDS, Purdue University, July 10, 2015 4
How Believable Are We ?
Do people in general believe our best radiation risk estimates ?
YES ________ NO ________
– WHY ?
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Why We May Lack Credibility ?Our risk assessments are too technical ?
Lack of understanding probabilities and uncertainty ?
People have other more credible sources ?
We are generally distrusted as scientists ?
Our estimates do not match up with what people have always heard ?
Why take risks, if not needed ?– Better to be safe from radiation , than sorry ?
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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Axioms on the Meaning of Radiation Risks ?
1. Radiation risks assessments have no inherent meaning,
they are just numbers,
until they are interpreted
2. The meaning of radiation risk assessments is whatever people believe it to be
Thus, the meaning of risks is highly subjective and variable
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Interpretation of Radiation Risks
Specialists in radiation safety may find common agreements on the meaning of radiation risks, because of similar technical understanding
Most of the world does not have that background or understanding and may interpret radiation risks very differently
Believability or different interpretation ?
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Have You Been Puzzled By - - ?How people can make such fast decisions for safety with little data or understanding
How they can be so sure of their decisions
How illogical they may seem
How emotions affect safety decisions
How people lack a number sense
Lack of understanding of magnitudes and probabilities
Lack of understanding randomness
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Radiation = FearsThe predominant factor in the evaluation
of radiation risks is FEAR
Fears are driven by Imagination of unacceptable consequences of radiation
Many do not care what the best risk estimates may be
They just “know” that radiation is to be avoided - as a reaction to gut fears
Anecdotes – “radiation safety,” oil field HPS PDS, Purdue University, July 10, 2015 10
Basis of Radiation FearsRelated to how our minds work for
processing information for safety
Studies in neuroscience show -
Its about survivalWe are constantly alert to dangers and
we make decisions accordingly
Our evaluations of radiation risks are prone to many errors
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Two Systems for Risk Decisions1. Conscious - Reason and rational analysis of facts
– Favored by technical specialists– May lead to intelligent decisions,
but, very slow and takes effort
– For radiation safety, we often do not have all the facts, time to gather facts,or knowledge to understand them
2. Subconscious - Emotion, instinct, and
gut reactions , very fast,
– Does not need all the facts– Origin of most decisions, especially for safety
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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Role of Our Conscious Mind < 1%
Slow, deliberate, rational, thinks, reasons, and makes decisions and choices based on sensory input
Source of knowing and awareness
Serves as the captain of our ship, the giver of orders
Analyzes information to make decisions
Can only deal with one thing at a time– Example
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Subconscious Mind > 99.999%The seat of our emotions / creativity.Takes orders from the conscious
mind without judgments
A Very Fast, super computerFunctions 24 / 7 operating the
machine we call our body– Regulates our heart, our breathing,
digestion of food, healing of cells, etcHandles thousands of inputs simultaneously
for our health and protectionProgrammed to fear / react instantly to danger
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How We Make Risk DecisionsWe process, sort, compare, categorize, and
correlate information, in relation to -– Immediate circumstances “Radiation OMG”– Experiences – what have we heard ?– Life factors, such as health, wealth,
traditions, and lifestyles– Loss aversion – need to be safe
With all these inputs we come up with instant judgments
– Quick judgments are crucial to survivalBased on limited information– May not be best in the long term– Is running away the best answer ?HPS PDS, Purdue University, July 10, 2015 15
Instant Subconscious Processing
Stimulus
Media Stories
Chernobyl
Fukushima Hiroshima
“Deadly Radiation”
X-rays
Response
Cancer
DeathFamily & Children
Property Damage
Loss Avoidance
“OMG – RUN !”
16
Fears of Radiation are InvoluntaryInstinctive fears of heights, snakes, spiders,
closed spaces, submersion, public speaking Repeated message “Deadly Radiation” for 70 yrs– Transferred to our subconscious mind for
protection as a frame of reference– Radiation is now an instinctive
source of fear– Thus, fear of radiation –
is not a conscious choiceSubconscious reacts automatically to
radiation without consulting the conscious mind
Decision to “RUN” is now automaticHPS PDS, Purdue University, July 10, 2015 17
What Does “Risk” Mean ?People often equate radiation with
cancer and death
For many people “risk” means the same as “chance”
Most are NOT willing to take a “chance” on getting cancer from radiation,
if it can be avoided
People generally do not understand risk probabilities
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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Probabilities and Radiation Risk
Dealing with randomness and probability is normal for health physicists
Radiation is a random phenomenon– All measurements are samples from a random
distribution and are only best estimates
The practice of ALARA is to minimize future random chance of cancer
We use LNT as a model for safety practices
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Calculated Risks –
How to Know When Numbers
Deceive You
Gerd Gigerenzer
Simon & Schuster2002
Franklin’s Law
Benjamin Franklin in 1789 wrote:
“Out constitution is in actual operation, everything appears to promise that it will last, but in this
world there is nothing certain but death and taxes.”
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From GigerenzerFranklin’s law helps us overcome the
illusion of certainty, But it does not tell us how to deal with risks
Primary conclusion from Gigerenzer - When thinking or talking about
risks, use frequencies rather than probabilities
– People often think in terms of whole numbers, not percentages or fractions.
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People Want CertaintyPeople want assurance and certainty
Perceptions provide useful images of our environment, as well as
feelings of comfort and safety
–Although not always correctUncertainty and risk are to be avoided
Even an illusion of certainty is preferable
Remember our minds are wired for survival
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Our Minds Create Certainty
Visual perception reflects this process
Necker Cube
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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Is seeing believing?
Good resolution for only 1 – 2 degreesof arc around retina’s center
We move our eyes to focus more widely
Our two eyes and brain interpolate to fill the gaps
We use our imagination to fill in gaps of nonvisual data.
We draw conclusions based on incomplete data and conclude our picture is clear
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Errors of the Conscious MindIs Seeing Believing ?
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Which tabletop is bigger ?
Roger Shepard -1990, Turning the Tables Illusion of Certainty
Our perceptual system (subconscious)
analyzes incomplete or ambiguous information and “sells” its best guess to our conscious mind as a definite product
Inferences about depth, orientation, andlength are provided automatically
Thus, even understanding the illusion does not change the perception of our conscious mind
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We Look But Do Not Always SeeWe skim – we do not read every letter
We look for patterns and anticipate what is coming
We notice on a need-to-know basis
As something becomes familiar, we tend to notice less , not more, and we come to see things not as they are, but as we assume they ought to be.
We could all benefit from a better understanding of our own limitations
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Can You Read This ?
If you can read this with ease,
you have an awesome talent.
This is both backwards and
upside down.
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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We Anticipate What is ComingWe rely on context to guide our
perception of everyday events
Encountering something out of context, makes recognition a lot harder
We need to know the context in order to process information
– Newspaper headlines
– Subheadings
– Photo captions
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Placebo EffectIf the conscious mind is convinced to
expect a positive effect, that message is sent to the subconscious mind, which does not judge, but proceeds to marshal resources to accomplish that expectation
Can be positive or negative
Examples– Retirement
– Death of a spouse
– Fukushima32HPS PDS, Purdue University, July 10, 2015
Natural FrequenciesOur minds have evolved dealing with
natural frequencies (whole numbers) for assessing risks
Probabilities and percentages are more recent inventions, not always understood
Our minds record frequencies of events, such as spatial and temporal locations of objects with little effort, awareness, or interference
– Again, its about survival
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InnumeracyInability to reason appropriately about
numbers, uncertainties, and risk
H.G. Wells (early 1900’s? ) - predicted “Statistical thinking will one day be as necessary for efficient citizenship as the ability to read and write.”
Early 2,000’s a weather man predicted 50% chance of rain on Saturday and 50% on Sunday and concluded there was 100% chance of rain on the weekend
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Innumeracy is Connected to -Illusion of certainty– Remember Franklin’s Law
Ignorance of risk– Aware of uncertainties, but not magnitude
Miscommunication of risk– Knows about risks,
but not how to communicate them
Clouded thinking– Knows about risks, but not how to draw
conclusions from them
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Interpretation of Probability
Degree of belief – subjective probability
Propensity - depends on properties of an object, such as the physical symmetry of a die. If the design, mechanism, or traits are not known, then there is no probability.
Frequencies – probability based on a large number of observations, defined as relative frequency for a specified reference class
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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What the World WantsTo deal only with absolutes
People do not want to know about uncertainty and probabilities
Most people just want to know,
“Am I safe or not safe?”They do not want to know about risk
estimates
When presented with a risk of 1 / 10,000– Many will conclude they are the 1
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How People Handle Probabilities
38
Not understanding risk probabilities– People substitute an easier question
–“How do I feel about getting cancer?”
The answer to this question does not require any technical understanding
– Eliminates dealing with randomness, probabilities, and uncertainty
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Horrors of CancerEveryone knows of the horrors of cancer
Prospects of cancer become anoverwhelming influence on decisions for radiation safety
While people may not be certain about the risks of radiation
–“They are certain that they do not want to become victims of cancer”
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How Hard Do we Expect People to Work ?
How much effort should people put
into understanding radiation risks?How hard should we expect to work to
understand how people make risk
decisions?
What is the incentive to commit this effort ?
Why should people change their views
about radiation ?
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Can We Ignore Public Fears of Radiation?
Do irrational fears influence public policy?
Should we protect the public from fear?
How do we justify expenses for reducing imaginary risks?
Isn’t this actually happening all the time?
How many of us are dealing with “real” risks?
How much of what we do is driven by public views (fears) of what is needed for safety?
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Patterns and Expectations
The illusion of patterns strongly affects our views on radiation risks
Paducah – Gaseous Diffusion Plant –reports of cancer incidence in many neighborhoods
How many people in Japan who may get cancer among the Fukushima evacuees will likely conclude that the Daiichi incident is the cause ?
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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Truth andThe Illusion of Knowing
We create good stories to explain the world around us and then we believe our stories
It is easier to construct a good story when we know little and have fewer pieces to the puzzle
– This might explain why some people are so convinced of the hazards of radiation
Stories confirm what we have always believed and what we have always known
What do we really know for sure ?
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David Ropeik
Bounded rationality
How people make decisions,
When –
1) Limited data
2) No time to get data
3) No understanding of data
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Daniel Kahneman
Ferrar, Straus, and Giroux,New York
2011
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Kahneman- A New VocabularyWords and definitions to describe
mental errors
To learn to recognize these errors in ourselves and others
We are too quick to accept information provided by our subconscious without analysis by our conscious mind
For efficiency our brains take shortcuts which lead to errors in judgement
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Subconscious Narrative
We attempt to create a story or narrative of our lives from information available
Since this information is limited to our experience, we often do not have the whole picture
Thus, we are prone to errors, especially for assessing risks
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Sources of Judgement Errorssubstitution, stereotyping, WYSIATI (what you see is all there is), causal explanations, base-rate neglect, the halo effect, the framing effect, the anchoring effect, narrative fallacy, illusion of validity, illusion of skill,
Overconfidence in what we think we know
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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We are Inherently Illogical
Because of the way our minds work, we cannot help but be illogical and irrational
People ignore statistical information and lead their lives based on causal connections and explanations
Our brains confuse the actual experience with the memory of the experience
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Errors of Perceptions
We do not passively notice the world
around us, instead our awareness of events is both selective and constructive
• Much of what strikes the eye or ear is never seen, heard, or remembered
• Much of what we think we have perceived or recalled, never actually happened
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RememberingWhen we recall a story, it doesn’t
simply become a version of the original event, it becomes the event as we remember it
Conversation is not always about imparting information or telling the truth, but about managing the impressions we make
Accuracy can take a back seat
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MemoriesMentally, people have two selves, experiencing-self and remembering-self.
The experiencing-self answers the question, “How are things right now?”
The remembering-self answers the question, “How was it, on the whole?”
Memories are all we get to keep from our experience of living.
Confusing experience with the memory of it, is a compelling cognitive illusion.
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Errors of Recall
We recall through rose colored glasses
We recall our past in a more favorable light
We reconstruct our memories in positive, self flattering ways
–Without knowing we are doing thisWe remember wins more than losses
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Can We Rely on Memory ?Alterations to the story become
incorporated into the memory of the storyteller and the storyteller then remembers things that may not have happened
We then come to believe our own untruths and are not aware of this happening
Brian Williams ?
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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The Availability Heuristic Occurs when the mind bases its
judgment on the probability of an event happening.
Where the probability is determined by the number of similar incidences it has stored in memory
And how easy it is for the brain to recall those incidences
– TMI, Chernobyl, Fukushima
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Subconscious PrimingExposure to a word makes it easier for
related words to be evoked. Action and emotions can also be primed. The influencing of an action by an idea, is known as the ideomotor effect.
Memory is susceptible to illusion.
Words that have been seen before are easier to see again.
This is known as the illusion of familiarity.
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Subconscious FunctionsStudies of brain responses have shown
that violations of normality are detected very quickly. Finding causal connections in a story is an automatic process of our subconscious mind
The main function of our subconscious is to determine what is “ NORMAL” in a our world.
It works to make connections to create a coherent interpretation of each situation.
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Subconscious ErrorsOur subconscious functions mainly by
jumping to conclusions.
This becomes risky when a situation is unfamiliar, the stakes are high, and there is no time to collect more information.
Our subconscious is biased to believe certain things, without evaluation
Our conscious mind is in charge of doubting and unbelieving.
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Subconscious ErrorsOur subconscious is very good at
building the best possible interpretation with the ideas that are available, but it does not consider ideas that it does not have. WYSIATI
Overconfidence - where the brain fails to realize that evidence is missing,
Framing - where different ways of presenting the same information evoke different emotions.
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Errors of our Conscious MindOur conscious mind is sometimes busy
and often lazy.
It often accepts almost anything the subconscious presents (Deadly Radiation)
Our conscious mind is set up for self-criticism, but its search for information and arguments is mostly constrained to information that is consistent with existing beliefs.
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Why People Do NOT Believe Our Best Radiation Risk Estimates
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Errors Due to Randomness
Our preference for causal thinking leads us to make serious mistakes when evaluating the randomness of truly random events.
Our downfall occurs because we are pattern seekers and believers in a coherent world.
Causal explanations of chance events are generally wrong.
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Interpretation of Small Risks
Many people have a basic limitation in the ability of their minds to deal with small risks.
They either ignore them altogether or give them too much weight, with nothing in between.
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Denominator Neglect
People overestimate the probability of unlikely events and give too much weight to their likelihood in their decisions.
Vividness and the ease of imagining are key factors in risk decisions
Denominator neglect helps explain why different ways of communicating risks vary so much in how they affect people.
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Fear of RegretRegret is an emotion and a punishment
we inflict upon ourselves.
Regret is usually accompanied by feelings that we should have known better.
If making a certain choice can cause harm or damage, that choice becomes a taboo trade-off
Because of the regret and shame it would cause.
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Vintage Books
New York
2012
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Nassim Nicholas Taleb
Random HouseNew York 2004
Why People Do NOT Believe Our Best Radiation Risk Estimates
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Nassim Nicholas Taleb
Random House New York2007, 2010
We are Naturally LazyThe “law of least effort” applies to both
cognitive and physical exertion. This law maintains that if there are several ways to reach the same goal, people will eventually go to the least-demanding course of action.
The brain seeks out ways to be more efficient.
Laziness is built into our nature.
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Limited Budget of EffortPhysical activity and deliberate thought
draw on the same limited budget of effort. They also show that maintaining a coherent train of thought requires discipline.
If someone gives you a math problem while you are walking – you will automatically stop to “think” about it
How much effort should people commit to understanding radiation risks ?
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We Can Do Only One Thing at a Time
Task Saturation – trying to do too many things at once
We cannot divide attention between two conscious activities
We may be conscious of two things happening at the same time, but we cannot make two conscious decisions at the same time
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Can We Multitask ?
Gains from multitasking are illusory
Our brains slow down when juggling multiple tasks
Switching from task to task can create problems – we forget what we are doing
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Role of the Subconscious Mind
Influences our conscious view of the world in fundamental ways
– How we view ourselves and others
– The meanings we attach to everyday events in our lives
– Our ability to make quick judgments
– The actions we take in response to instinctive experience of the world
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First Vintage Books Edition, May 2009
Leonard Mlodinow
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Leonard MlodinowThe Drunkard’s Walk – How
Randomness Rules Our Lives
Anecdote of lottery winner– 7 X 7 = 48
“We create our own view of the world and then use it to filter and process our perceptions, extracting meaning from the ocean of data that washes over us
– And we are often prone to errors”74HPS PDS, Purdue University, July 10, 2015
Human IntuitionNot suited to situations involving
uncertainty
People cannot create or recognize random numbers
Neuroscience looks at how people make decisions when faced with imperfect or incomplete data
When chance is involved, our intuition may be prone to substantial errors
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When Chance is InvolvedIntuitive processes are
seriously flawed
We often make poor decisions when confronted with randomness or uncertainty
Difficult task to swim against the tide of human intuition
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Adding Details
If added details fit our mental picture
– The more real it seems and the more probable
However, adding less-than-certain details to a conjecture makes the conjecture less probable
It is common to assign higher probabilities to contingencies that are described in more detail
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Uncovering the TruthThe understanding of randomness can
reveal hidden layers of truth, but only to those who possess
the tools to uncover them.
Our brains are not wired to do probability problems very well.
We determine the “truth” intuitively
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Perception and Reality
Human perception is not a direct consequence of reality, but rather an act of imagination.
Perception requires imagination because the data that people encounter in their lives is never complete and always equivocal
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How is Randomness Seen
People have a very poor conception of
randomness. They do not recognize it
when they see it and they cannot
produce it when they try.
Our minds are wired:to assimilate data, fill in the gaps, and look for patterns
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Confirming PatternsEven random patterns can be interpreted
as compelling evidence,– If they relate to our preconceived notions
But by confirmation bias we are focused on finding and confirming patterns rather than minimizing false conclusions
Big step – to question our perceptions and theories. Should we spend time
looking for evidence that we are wrong ?81 HPS PDS, Purdue University, July 10, 2015
Role of ThinkingOur minds do not seem made to think
deeply and introspect
Good thing, otherwise an introspective ancestor would have been eaten by a lion
Consider that thinking is time consuming and often a great waste of energy
We actually do much less thinkingthan we think we do.
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Speedy Perceptions
We are good at sizing up a situation
We can extract meaning in 1/10th of a second
The price for such speed is that we miss a lot of details
The problem is that we do not “think” we missed anything
We are not wired the way we think we are
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We Cannot Unlearn
Hard to ignore or unlearn bad information,
Even when we know it is wrong
Overconfidence is a leading cause of errors
Memory is more of a reconstruction, rather than a reproduction
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Finding Meaning is Automatic
We search for meaning – not the details
Difficult to force ourselves to remember meaningless information
Why we forget passwords and hiding places – We equate “unusual” to memorable,
when in fact it is the opposite
We extract meaning, even when not aware of doing this
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We Do Not Know We are Biased
Instant judgements have profound implications for rationality of many decisions
When we do not know that we are biased,
eliminating mistakes due to bias can be very difficult
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Meaning of Risk ?
Our conscious mind is concerned with how risky “it is”
Our subconscious mind, where risk decisions are made, is concerned with how risky “it seems”
That perception depends on how the risk is framed
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Ignorance of Risks
In a democracy we are swamped with information (statistics) , much of which is not understood
Major forms of miscommunication– Single event probabilities
– Relative Risks
– Conditional probabilities
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Single Event Probabilities
Can be confusing:– Because there is no reference class
– No comparable events known
– Thus, probability is only a guess
– People tend to fill in the reference class according to their interests of concerns
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Relative Risks
A drug company may say a certain drug will reduce risk of dying by 22%
Some may believe this means 220 out of a 1,000
Actually it means that without the drug, 41 out of a 1,000 will die and with the drug only 32 will die – a 22% difference
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Conditional Probabilities
The probability of an event occurring given that another event has already occurred is called a conditional probability.
The probability that event B occurs, given that event A has already occurred is
P (B|A) = P (A and B) / P (A)
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The Effect of Timing
When consequences of our decisions are far off, we are prone to bigger gambles,
When consequences are more immediate, we tend to be more conservative
I wonder how people generally view the immediacy of radiation effects ?
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Truth and Subconscious BiasWe tend to believe what confirms our views
and to discount other information
Thus, we may accept data from small samples
We may judge on basis of how information “resembles” something we already know
We draw conclusions based on“ease of recall”
– This may be function of media coverage
– Paradox, media reports what people want to see
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Source of Quick Responses
Responding quickly to threats or to promising opportunities improves the chance of survival.
Our subconscious takes over in emergencies and gives priority to self-protective actions.
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Response to Threats
Human brains are designed to give priority to bad news. This evolutionary history is reflected by the automatic operations of our subconscious
Threats are recognized and given priority over opportunities as a survival technique.
Loss aversion is one of many manifestations of broad concerns for survival
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Review - SubconsciousConstantly monitors all inputs to predict
and avoid imminent danger
Anything unusual, such as radiation, triggers a search of all knowledge and memories to decide if protective action is needed
Most will conclude that radiation is bad
Without technical knowledge, they may not be able to defend this decision , but deep in their gut, they know this is true
Imagination of unacceptable consequences of radiation will win out every time.
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Summary
This has been a very quick review of how people evaluate risks and why they may not believe our best risk estimates
Or, how they interpret risks differently
Our minds are programed for survival to make quick judgements about risks and decisions for safety
Such judgements are PRONE to ERRORS
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Ways we are Prone to ErrorsWe use mental shortcuts for quick decisionsDecisions by subconscious mind are crucial
for safety – especially for imminent danger– Does not do well for dangers that are not
imminentSubconscious acts on impressions which may
not be based on good information– Not based on evaluations and therefore it has
no clues to errors or biasesConscious mind is not inclined to second guess
subconscious decisions – Wants to conserve energy
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Sources of Errors In Safety Decisions -
“To err is human”
We are all afflicted with systematic biases in the way we see, remember, and perceive the world around us
Our expectations shape the way we see the world, and the way we act
These effects occur subconsciously
We are biased and don’t know it
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ConclusionsWhy do people not believe our best risk
estimates ?
People often do not understand what risk numbers mean
Differences in Interpretation– Based on fears
– How our subconscious processes information for survival
– These processes are prone to many errors
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References
How Risky is it Really, David Ropeik, 2010Thinking, Fast and Slow, Daniel Kahneman,
2011The Drunkard’s Walk – How Randomness Rules
Our Lives, Leonard Mlodinow, 2008Subliminal – How Your Unconscious Mind Rules
Your Behavior, Leonard Mlodinow, 2012Human Error, James Reason, 2009Why We Make Mistakes, Joseph T. Hallinan,
2009 The Psychology of Risk, Glynis M. Breakwell,
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ReferencesCalculated Risks, Gerd Gigerenzer, 2002
Unlimited Power, Anthony Robbins, 1986
The Black Swan – The Impact of the Highly Improbable, Nassim Nicholas Taleb, 2010
Fooled by Randomness – The Hidden Role of Chance in Life, Nassim Nicholas Taleb, 2004
The Genie Within Your Subconscious Mind, How it Works and How to Use it. 2009Harry W. Carpenter
The Power of Your Subconscious Mind. 2008Joseph Murphy
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References
McIntyre, Leslie (2012-07-26). Quicklet on Nassim Taleb's The Black Swan (CliffNotes-like Book Summary and Analysis) (Kindle Locations 66-70). Hyperink - Black Swan Book Summary and Analysis. Kindle Edition.
Summaries, Instaread (2014-04-04). Thinking, Fast and Slow by Daniel Kahneman –A 30-minute Summary. Kindle Edition.
Montaqim, Abdul (2012-02-23). Quicklet on Nassim Taleb's Fooled by Randomness (CliffNotes-like Summary) (Kindle Locations 74-76). Hyperink Book Summary, Analysis, Commentary. Kindle Edition.
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Questions ?
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