Showing posts with label cognition. Show all posts
Showing posts with label cognition. Show all posts

Wednesday, September 14, 2022

Noise: A Flaw in Human Judgment


Noise: A Flaw in Human Judgment


   Daniel Kahneman, Olivier Sibony, and Cass R. Sunstein

Reviewed by

  Geoffrey W. Sutton


We are constantly exposed to opinions. Some of those opinions are judgments. And some of those judgments affect our opportunities to work, obtain healthcare, receive fair treatment by government entities, and earn fair evaluations in school. Some people are paid to make informed judgments. Unfortunately, some judgments are noisy—they vary. Noise is about the differences in judgments that affect our lives.

When the authors provide examples of variation in judgments, they are writing about variability in a statistical sense. As a retired professor who taught research and statistics to undergraduate and graduate students, I’m not sure the authors were entirely clear—at least not clear enough for readers who are either new to the concept or haven’t drawn on their statistics knowledge for some years. In any event, I think the book deserves a look because it draws attention to a real problem—a problem with which I’m familiar.

The authors often provide examples of judges in the criminal justice system. For example, they note that judges can vary in the length of a sentence for the same offence. They also provide examples of different diagnoses provided by physicians for the same set of symptoms—this is especially true in the diagnosis of mental disorders.

The authors introduce the problem of variation in judgments by referring to shots at target. Given a group of people firing at a target, there will likely be some variation. If they are experienced, we would expect them to be close to the bullseye. The degree to which the holes are scattered is variance. The variation is like noise in judgments, which deviate from accuracy. Those deviations represent error.

Let me suggest dropping the term variance in judgments in favor of differences. We can expect people to have differences of opinions about one thing or another but when it comes to a medical diagnosis, we want an accurate decision. When different experts arrive at different diagnoses, that’s noise. And that can be scary when the diagnosis leads to very different types of treatment.

Bias is a related concept. Bias is a systematic type of error. Using the target analogy, bias reveals a tendency for all the deviations from the bullseye to be located in the same area. In psychology, it might be a tendency for some clinicians to diagnose anxiety rather than ADHD or ADHD rather than anxiety when observing fidgety children. Bias can be found in numerical scores too such as when some psychologists tend to obtain lower scores than others on intelligence tests.

The authors also cover the problem of transient differences or occasion noise. That’s the kind of inconsistency that can happen when the same person looks at the same data but comes up with a different judgment on two different occasions. The authors mention some well known influences like time of day and hunger affecting judgments.

I’ll skip ahead to their recommendations. After providing us with additional terms and many examples, the authors offer suggestions for controlling unwanted noise. One major suggestion is to rely on algorithms based on the evidence that computerized assessment of all relevant data can often beat human decision-makers in accuracy. The authors recognize this won’t sell well to a lot of readers but they do offer a defense against common objections.

A second, and in my mind more palatable approach is to create a structured approach to decision-making. This can be as simple as guidelines, checklists, and preset questions to use in various fields. In applied psychology and counseling, students learn to use checklists and decision trees when making a diagnosis. Others learn to use scales and questionnaires and ways to aggregate available information relevant to both diagnoses and treatment plans.

There’s a lot more in this book both in terms of examples of noise as well as suggestions for reducing noise in different areas of life. They supplement their work with useful appendixes: How to conduct a noise audit, A checklist for a decision observer, correcting predictions.



Kahneman, D., Sibony, O., & Sunstein, C.R. (2021). Noise: A flaw in human judgment. New York: Hatchette.


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Tuesday, January 25, 2022

The Seven Sins of Memory- Book Review & Resources


The Seven Sins

  of Memory


Daniel L. Schacter     


Reviewed by

  Geoffrey W. Sutton

Schacter’s Seven Sins of Memory is like a fine seven course meal. Each course serves up an interesting collection of research that’s easy to read by the general public and pleasantly presented, yet rich with enough details to appeal to scholars and practitioners. I left feeling satisfied.

Every mental health clinician and all who work with people should read about the seven sins of memory and come back to it when they wonder about memory complaints or detect discrepancies in recall.

Students will find it helpful too as Schacter weaves psychological science into meaningful stories—a good example of how to write about psychological science for nonpsychology majors.

I must say that I found the notion of “sins” strange—is this a psychology of religion book? I suppose it could be. Afterall, religious scholar Craig Keener included a discussion of memory in his book about the Gospels and the Life of Christ. However, the sins of memory are the problems with human memory—problems that can deceive us and lead to inaccurate conclusions. We can miss the mark and we may need forgiveness.

I’d like to suggest a title: Memory: Seven Reasons for Humility. But then again, I’m not a best selling author or a famous psychological scientist.


There’s so much in this book. In this post, I will just note some of the key features of each chapter so you get a sense of what this is all about.

Problems of Forgetting

1. The Sin of Transience

We forget names and other things as time passes. Memory fades. Memories are fleeting- transient. We have less mental reserve as we age. How much we remember is linked to how much we elaborate on new information when forming a new memory (encoding).

2. The Sin of Absent-Mindedness

When we are distracted, we may not capture sufficient information to form an adequate memory—we are absent-minded. We can also be distracted, which can  lead to impaired recall of a memory. The phenomenon of change blindness fits here too.

3. The Sin of Blocking

Name blocking is so common and serves as a quintessential example of blocking. Sometimes, information seems like it’s on the tip-of-the-tongue – a well-known phenomenon in memory research.

When Memory is Present but Wrong

4. The Sin of Attribution

We can make errors in recall when our memories store misattributions. This can be serious when people falsely accuse someone of a crime because they have seen someone else’s familiar face and stored it along with the offense. Psychologists refer to memory binding—connecting various bits of information into a memory, which isn't really a record of our personal experience.

5. The Sin of Suggestibility

The questions we ask can influence what people recall when they provide answers. Questions are so powerful that people have recalled events that never happened. Suggestibility can create false memories. Obviously this can, and in fact has been, a serious problem when witnesses to a crime are interviewed about what they saw or heard. Not surprisingly, Schacter refers to the work of Elizabeth Loftus.


6. The Sin of Bias

Our memories can be influenced by present experiences. We tend to recall the past in ways that are consistent (consistency and change biases) with our present. 

Current knowledge influences what we think about the past--that's hindsight bias. We serve ourselves well in egocentric biases. 

And our  stereotypical biases combined with recall of memories can affect our views about people and experiences in the present.

Schacter includes a useful analysis of the power of fake news to influence our beliefs. Mere repetition appears to strengthen beliefs in fake news (the illusory truth effect).

 Persistence and Distressful Memories

7. The Sin of Persistence

When memories persist, we can re-experience pain and humiliation. Emotional experiences act to highlight certain experiences and not others. Emotions can also impair what we remember about an event when we focused on the threat and did not perceive other details of the event. Thus, because we focused on the threat, our memories are incomplete. Our current mood can influence the nature of memories we recall.

The Seven Sins: Vices or Virtues

In Vices and Virtues, Schacter suggests ideas about how our problems with memory may have developed. And he cites some evidence suggesting how our problems may be beneficial that is, virtues. For example, the gradual fading of some memories can relieve us of the burden of nonuseful details and may even lessen the pain of bad experiences. Even trauma can serve us when it allows us to avoid similar painful situations in the future.


I praised the book at the beginning and conclude with a clear statement that I recommend this book. I say this as a psychologist with years of experience testing the memories of children and adults in clinical practice and for the courts. I have also consulted in numerous cases of people claiming disability due to memory impairment.

I suggested a different title: Memory: Seven Reasons for Humility. In addition to the applications suggested by Schacter, I add a lesson in humility. Even those blessed with the best brains must deal with the common problem that our memories can lead us astray thus, a dose of humility in warranted. Though some people are undoubtedly out to deceives us and spin their misdeeds into golden memories, others are simply mistaken. Great interviewers will be mindful of the frailties and strengths of human memory. And many of us will need forgiveness.

Our memories are precious. Without adequate memories, we lose a sense of self-identity—who are we without a memory?


Cite this review

Sutton, G. W. (2022). The sevens sins of memory: Book review & resources. SuttonReviews. Retrieved from


Book Reference

Schacter, D. L. (2021). The seven sins of memory: How the mind forgets and remembers, updated edition. New York: Mariner. (Kindle Edition)

Book details: 532 pages, Preface to the updated edition, Introduction, 7 chapters- one each for the 7 sins, A final reflections/ideas chapter, notes, bibliography, end material.

About the book author

Daniel L. Schacter is the William R. Kenan Jr. Professor of Psychology at Harvard University.

Available as





Please check out my website

   and see my books on   AMAZON       or  GOOGLE STORE

Also, consider connecting with me on    FACEBOOK   Geoff W. Sutton    

   TWITTER  @Geoff.W.Sutton    

You can read many published articles at no charge:

  Academia   Geoff W Sutton     ResearchGate   Geoffrey W Sutton 


Related works

Thinking, Fast and Slow by Daniel Kahnemann

Christobiography: Memory, history, and the reliability of the gospels by Craig Keener.

The myth of repressed memory by Elizabeth Loftus & Katherine Ketcham

The malleability of memory with Elizabeth Loftus by Howard Burton

Picking Cotton: Our memoir of injustice and redemption by Jennifer Thompson-Cannino and Ronald Cotton


Daniel Schacter on The Seven Sins of Memory on YouTube