I found the examples for hindsight bias (the tendency to believe that you've always believed what you believe now or to find things obvious in retrospect without remembering that you didn't know it before) in this
post quite strange.
The author shows the results of two fake studies (with the conclusions "you can't teach a dog new tricks" and "you're never too old to learn") and says in effect, Gotcha - you believed both of them, didn't you! You're not so smart! He suggests this as an explanation: "Both of those fake studies seemed probable because when you learn something new you quickly redact your past so you can feel the comfort of always being right."
This is an odd take for several reasons, including fact that most people started reading this post
already believing that both statements are true. I don't think that reading about these studies caused most of us to "learn something new" at all (though we were not familiar with the specific research that supported these beliefs, neither idea is novel).
He points to an actual study in which people read contradictory proverbs and evaluated them as true, e.g. that both "love is stronger than fear" and "fear is stronger than love" are true. He suggests that this provides evidence for hindsight bias.
It is a common observation that people often think that the science of psychology (particularly social and personality psychology) doesn't tell us anything we don't already know - that it's basically all "common sense."
In some cases, this probably is a matter of hindsight bias. For example, the
Asch conformity experiments (people give incorrect answers to an easy visual perception task because other participants gave that answer), the
Milgram experiment (people are willing to give others levels of electric shock they believe are lethal when instructed to by an experimenter), and studies of the
bystander effect (a person in trouble is less likely to get help the more observers there are) give classic examples of counter-intuitive findings from social psychology. Once people become familiar with these findings, they may forget that they ever believed anything to the contrary.
However, I think finding contradictory statements from psychological research both true and obvious demonstrates a different kind of common effect: the illusion of explanatory depth.
People think they know more about things than they actually do. We often think we know how something (such as a machine) really works, but when challenged to explain it, it is clear that our understanding is rudimentary and facile at best. We have only the most cursory, simplistic understanding of a lot of things yet think of ourselves as very knowledgeable, hence, our sense of having "explanatory depth" is illusory. (For empirical research on people's understanding of how objects work, see: Rozenblit, L., & Keil, F. (2002). The misunderstood limits of folk science: An illusion of explanatory depth.
Cognitive Science, 26, 521-562.)
I believe the same illusion is at work with people's understanding of psychological processes and thus their evaluation of psychological research as only demonstrating ("proving") the obvious. I think part of this illusion arises from the fact that most people view psychological research in terms of establishing various facts, such as that birds of a feather flock together and that opposites attract. But figuring out the "what" is just a small part of the scientific enterprise. We're also very interested in "how" (understanding the mechanisms of the process in detail), "when" (what are the boundary conditions on the effect - i.e., under what parameters do the claims hold), and sometimes "why" (what purpose does it serve). People often conflate description with explanation, perhaps not even realizing that there are other levels of understanding beyond the one they have.
In the introduction to my undergraduate social psychology textbook, the author describes the kinds of responses he gets when people at a party ask him what he does and he says that he is a social psychologist. In addition to the Fraidy-Cats who get frightened that he is going to try to "psych" them out and the Know-It-Alls who proclaim formal psychology to have no bearing on the Real Social World, he has to deal with Mini-Experts who "take the opportunity to instruct me in their favorite theories of why various parts of the social world do or do not function effectively; unfortunately, this is often about as illuminating as hearing a medieval monk discuss the workings of the modern automobile." (Schneider, D. J. (1988). Social psychology.)
Of course, people's understanding of psychology is much worse, even at the basic factual level, than they think it is. The recent book
50 Great Myths of Popular Psychology (a book I have not seen or read, but want to read) outlines these errors. How many of these ideas do you (or did you, if you can overcome the hindsight bias) believe? I have believed a lot of them.
1 Most People Use Only 10% of Their Brain Power
2 Some People Are Left-Brained, Others Are Right-Brained
3 Extrasensory Perception Is a Well-Established Scientific Phenomenon
4 Visual Perceptions Are Accompanied by Tiny Emissions from the Eyes
5 Subliminal Messages Can Persuade People to Purchase Products
6 Playing Mozart’s Music to Infants Boosts Their Intelligence
7 Adolescence Is Inevitably a Time of Psychological Turmoil
8 Most People Experience a Midlife Crisis in Their 40s or Early 50s
9 Old Age Is Typically Associated with Increased Dissatisfaction and Senility
10 When Dying, People Pass through a Universal Series of Psychological Stages
11 Human Memory Works like a Tape Recorder or Video Camera, and Accurately Records the
Events We’ve Experienced
12 Hypnosis is Useful for Retrieving Memories of Forgotten Events
13 Individuals Commonly Repress the Memories of Traumatic Experiences
14 Most People with Amnesia Forget All Details of Their Earlier Lives
15 Intelligence Tests Are Biased against Certain Groups of People
16 If You’re Unsure of Your Answer When Taking a Test, It’s Best to Stick with Your Initial Hunch
17 The Defining Feature of Dyslexia Is Reversing Letters
18 Students Learn Best When Teaching Styles Are Matched to Their Learning Styles
19 Hypnosis Is a Unique "Trance" State that Differs in Kind from Wakefulness
20 Researchers Have Demonstrated that Dreams Possess Symbolic Meaning
21 Individuals Can Learn Information, like New Languages, while Asleep
22 During "Out-of-Body" Experiences, People’s Consciousness Leaves Their Bodies
23 The Polygraph ("Lie Detector") Test Is an Accurate Means of Detecting Dishonesty
24 Happiness Is Determined Mostly by Our External Circumstances
25 Ulcers Are Caused Primarily or Entirely by Stress
26 A Positive Attitude Can Stave off Cancer
27 Opposites Attract: We Are Most Romantically Attracted to People Who Differ from Us
28 There’s Safety in Numbers: The More People Present at an Emergency, the Greater the Chance that Someone Will Intervene
29 Men and Women Communicate in Completely Different Ways
30 It’s Better to Express Anger Openly to Others than to Hold It in
31 Raising Children Similarly Leads to Similarities in Their Adult Personalities
32 The Fact that a Trait Is Heritable Means We Can’t Change It
33 Low Self-Esteem Is a Major Cause of Psychological Problems
34 Most People Who Were Sexually Abused in Childhood Develop Severe Personality Disturbances in Adulthood
35 People’s Responses to Inkblots Tell Us a Great Deal about Their Personalities
36 Our Handwriting Reveals Our Personality Traits
37 Psychiatric Labels Cause Harm by Stigmatizing People
38 Only Deeply Depressed People Commit Suicide
39 People with Schizophrenia Have Multiple Personalities
40 Adult Children of Alcoholics Display a Distinct Profile of Symptoms
41 There’s Recently Been a Massive Epidemic of Infantile Autism
42 Psychiatric Hospital Admissions and Crimes Increase during Full Moons
43 Most Mentally Ill People Are Violent
44 Criminal Profiling Is Helpful in Solving Cases
45 A Large Proportion Of Criminals Successfully Use the Insanity Defense
46 Virtually All People Who Confess to a Crime Are Guilty of It
Skills and Pills: Myths about Psychological Treatment
47 Expert Judgment and Intuition Are the Best Means of Making Clinical Decisions
48 Abstinence Is the Only Realistic Treatment Goal for Alcoholics
49 All Effective Psychotherapies Force People to Confront the "Root" Causes of Their Problems in Childhood
50 Electroconvulsive ("Shock") Therapy Is a Physically Dangerous and Brutal Treatment