Critical Thinking

FALLACIES LEADING TO ASSUMPTIONS OF COMMON SENSE

Common Sense Definition: We think of Common Sense as what is obvious or well known to one person or group. This view sometimes leads us to accept certain fallacies:

1. Assumption of Common Knowledge
2. Cultural Norms
3. Something Sounds Plausible: It seems to make sense
4. Attribution and Attribution errors
5. Projection of One's Ideal Self onto a Situation or onto Others
6. Pre-Pubertal Learnings

 
 

You know it so well that you think everyone should know it. It seems obvious (even if in error).

It seems to be Common among all people. Some examples would be:

• Instructions or car repair manuals.
• # of teats on a cow.

Common Sense breaks down when it is provided as INSTRUCTIONS. The reliance upon Common Sense when giving instructions pre-supposes that the receiver of the instructions already has a grasp on the subject, and therefore needs no specific detail. Some examples will illustrate:

• 1. When deciding whether to walk on the ice of a frozen lake, use Common Sense
• 2. When directing kids on the Internet, use Common Sense.
• 3. An anthropologist preparing to visit a tribe that has never had contact with outsiders, use Common Sense.
• 4. Deciding whether to eat a wild plant (mushroom), use Common Sense.
• 5. Deciding which used car to buy, use Common Sense.
• 6. Working around high voltage electricity, use Common Sense.
• 7. Parenting, use Common Sense.
• 8. Making investments in stocks, art, mutual funds, real-estate, friends' great business ideas, use Common Sense.
• 9. In gambling, so you win and don't lose, use Common Sense.
• 10. To quit smoking or lose weight, use Common Sense.
• 11. During a first aid emergency, use Common Sense.
• 12. If you get stuck in the woods over night, use Common Sense.
• 13. When traveling in a foreign country, to be sure you don't offend people, use Common Sense.
• 14. If you are alone when you go into labor, keep your head and use Common Sense.

• "Call before you dig"
• "Call 911"
• "Never eat a mushroom you aren't ABSOLUTELY SURE is safe to eat..."
• "If lost, stay put, let others find you..."

Check out the following excerpts from a Wall Street Journal article by Jim Carlton --

• Compaq is considering changing the command "Press Any Key" to "Press Return Key" because of the flood of calls asking where the "Any" key is.
• An AST customer was asked to send a copy of her defective diskettes. A few days later a letter arrived from the customer along with Xeroxed copies of the floppies.

Many books are written with titles such as A Common Sense Approach to Parenting. Then in the subtitle or description, it tells us that this wonderful volume provides "a step by step" or "comprehensive" or "detailed method". If the approach is truly common sense, then do we need to be told the steps, do readers need to comprehensive coverage and details?

Politicians and other persuasion professionals touting Common Sense:

How often have you heard politicians saying, "What we need is a common sense approach to..." then insert any topic. This way, listeners are likely to interpret an undefined statement in a way that fits their own beliefs. After all, people are apt to think their beliefs are "only common sense". This way, the speaker has won over the listener by the listener making the case to him/herself for the speaker!

Every culture & subculture has norms which the members grow up immersed in, so they come to be second-nature, often confused with first nature or HUMAN NATURE

Examples:

• Should kids in trouble look their parents in the eye?
• Touching vs. non-touching cultures
• Americans drive on the RIGHT side of the road, the English drive on the WRONG? Or LEFT? How do we think of this? Why?
• Hygiene and Food Preferences illustrate much of cultural norms and what violates them. Consider the shaving alternatives for women. Women in the USA typically shave legs and arm pits. Women elsewhere do not. In the USA, eating peanut butter & jelly sandwiches is as American as, well, as apple pie. In Holland, PB&J may be seen as disgusting because you would not mix the sweet with the salt!

Watch for each of the Logical Fallacies.

Cliches generally have a reverse cliche:

• Opposites Attract, but Birds of a Feather Flock Together.

bias on a foundation lacking evidence or facts.

• The TV ad for the Law Firm (mentioned above)..
• The moral argument of alcoholism - "If you reallyloved your family, you'd quit."
• Juvenile Delinquent Magazine sales - "Buy these from me to keep me off the streets..." Are there are no other options? - Sell magazines or hang out and commit crime on the streets.
• Scapegoating - "space aliens," "the government," "big business," etc. - Blaming otherwise unexplainable events on aliens explains what we do not understand about space & technology. Blaming what we have little or no perceived control over can be explained away by scapegoating onto the government or big business.

In general, attributions are ways we explain cause and effect relationships. For example, the way you interpret your own behavior, and that of others, may be very different from the way a third party observer might interpret those same behaviors. Often, there is a self-serving bias in these interpretations.

There are dispositional attributions (some characteristic of the person) and situational attributions (some characteristic of the environment). We tend to use each type in explaining our own, and others', behavior in a way that makes us look good to others and feel good to ourselves.

Fundamental Attribution Error -

• If I win the game: I am skilled, you are incompetent.
• If I lose the game: I was unlucky, you were lucky.

• Doctors save your kid's life, do you thank God? Why?

• My elderly uncle attributed his longevity to this suggestion, "Drink beer & whisky, not water" and based this advice on what water does to plumbing (corrosion and deposit build-up).
• Superstitions in general. For example, "this is my lucky bowling shirt."

Correlation exists when changes in one variable are associated in any way with changes in another variable. Causation exists when changes in one variable make another variable change.

These things are actually correlated:

• Number of deaths by drowning is correlated with an increase in soft drink sales.
• Sales of Ice Cream is correlated with murder rates.
• Number of golf courses built and the divorce rate are correlated.

The central issue: CORRELATION DOES NOT SHOW CAUSATION!

Simply because two things occur at roughly the same time and place does not mean that there is any direct or indirect association between them.
Examples:

A. I once had a student argue that the elimination of prayer in schools CAUSED the downfall of American greatness.

This requires:

• acceptance of certain term definitions. Has prayer truly been eliminated, or merely "organized prayer" or "mandatory prayer"? It has been said that as long as there are math tests, there will beprayer in school! What is meant by "downfall"? What aspects of America's greatness are in this downfall?
• denial of any other cause. If some downfall of American greatness is actually happening, could anything else be causing it?
• assuming that any downfall started then. The famed quotation, "The youth of America is going to hell in a hand basket" dates back to early American colonization, when people commonly carried hand baskets. It was felt that the youth ran wild and undisciplined, compared with fond memories of Europe and children who were seen and not heard.
• assuming that it is even really happening. Considering the conveniences and the state of wealth, world power, and scientific and medical progress, where is the downfall? Depending on how downfall is defined (probably along a moral degree) we might have to take a closer look at the actual facts, not something spouted from a biased perspective that might foster an anxiety intended to maximize a "we vs. they" mentality.

During the 1800's many persons with mental retardation and mental illness were diagnosed as having these conditions as a result of masturbation. Dr. Kellogg of Battle Creek, Michigan reportedly developed the bland cereal grain diet to reduce aggressive and sexual urges and impulses, including the idea that such a diet would prevent masturbation and its supposed relation to a "wasting away" of the person's physical and spiritual strength.

Here lies the premise that psychotherapy CAUSED the world to get worse. Again, we must consider questions similar to those from example 1 above.

• Is the world really Worse?
• Is it the FAULT of Psychotherapy?
• Have people taken advantage of Psychotherapy?
• Has psychotherapy perhaps slowed whatever rate of decline there would have been?

More information on evaluating Causal (Empirical) Arguments 

We often compare ourselves to others and their behavior, at times when we are NOT placed in the same difficult positions those other people have been in. Because we have all the details of how things worked out in the end, and are under none of the pressure to perform on the spot, we are prone to identify how we would most like to have performed in that same situation - fully believing that this would indeed be the actual behavior we would engage in.

Example: Many peoples' reaction to Milgram's experiment on obedience, using electric shocks to punish people for failure to memorize a list of word pairs, is to say, "I wouldn't do it. I would not zap someone with painful shocks to the point that they scream, or even might be dead." When confronted with the fact that all persons provided at least some shocks, and two-thirds of subjects delivered shocks to the point that they believed they had killed the other person, many people respond, "I have morals! I would be the one heroic person who would not do as told!"

Example: Recently I got home from shopping to find the clerk had put the receipt and my check into the shopping bag. Shall I return the check to the store or do I keep the freebie?

• Of course the morally right thing is to return the check, and most people claim they would do this.
• How many would actually return the check if put in this position?
• What do you think I did?
• Why? - Have you applied to me the same assumptions as you applied to yourself?

Subtype of Projection of One's Ideal Self onto a Situation or onto Others :
20/20 Hindsight for Others:

The essential character of this item is: "I see (NOW) that what you did would not work out.

It's obvious (now that it's over) that it could not work. I would have known this, and it is only common sense that you should have known it too."

• Example: The Monday Morning Quarterback is a common phrase/example that illustrates this. After the game is over, and we know what did and did not work for the team, it is easy to say what would have been a better strategy. It is much harder to do this under the pressures and ambiguities of the actual game!
• Example: I once had a student who worked as a Paramedic. He told the story of being on a difficult call during which his team was faced with a patient with ambiguous diagnostic signs. The team made the wrong choice in diagnosis and treatment resulting in a patient whose condition worsened. After the team arrived at the emergency room and a full diagnosis was made by the doctors, another paramedic said boldly that he would have known what to do and made the right diagnosis. Surely this was easier to do once the doctor and medical tests had done their diagnostic work!
• Example: Suicide prediction and prevention. Once a person has made the suicide attempt, people will suddenly start noticing what had been the signs they had missed, then mistakenly believe they "should have known." Certainly, it is easier to predict this type of event after there is clear evidence that the person is not merely being withdrawn or morose, but actually provides concrete evidence that there is something profoundly wrong going on.

Ideas and information developed & unchallenged before puberty are difficult to unseat. According to Piaget, the mode of learning and thinking changes at about the age of puberty into what is called Formal Operational Thought. With formal operations, we can more readily see and accept the gray areas in ideas, consider internal consistencies and inconsistencies, question assumptions that underlie ideas and values, more readily accept relative and abstract arguments and concepts. However, what we have learned prior to this generally remains unchallenged and continues to be perceived as "reality" based upon the credibility of the source under the criteria for credibility used at the time the material was learned - Parents, Teachers, Preachers, etc. Kohlberg referred to the level of moral development called "morality of authority" in which what is perceived as truth is that which an authority figure has stated is truth. If what seems a credible authority says something is true, there is no further need to challenge it.

Consequently, I find in my college classes that I have high credibility when taking a position with which my students already agree, or about which they have no prior knowledge. If, like with much of the discussion of Common Sense, I am introducing something contrary to their preconceived notions, I am told I am "just plain wrong" no matter how consistently the scientific data support my point.

Consider this statement:

"I find teaching of science fairly easy... my difficulties are with science re-education. If I can teach something about which the students have never heard, I find that they generally both welcome and understand it. It is when I have to teach them about something that they have already learned incorrectly, that I start to identify with Sisyphus."

"Rational explanations of why some previous belief might be incompatible with the behavior of nature, and a careful explanation of the actual behavior of nature is of little avail... I can usually only convince a small fraction of the students. The rest know in their hearts that their grade-eight teacher, say, or their mummy was actually right and that you are just a contrarian who is attempting to destroy the established order. The damage is done, the mind is frozen, and the pre-pubescent dogma lasts a lifetime."

(Source: Alistair B. Fraser. www.ems.psu.edu/~fraser/BadScience.html)

Examples:

• Time out vs. Spanking (Time Out can work very effectively, if it is done right!)
• Reinforcement is more effective than Punishment. (If you make the desired, effective, appropriate behavior pay off for the person or animal, they won't need to engage in the harmful, dangerous, or inappropriate behavior.)
• Freud & Sex - Many of my students comment on exams that Freudian theory is all about sex, despite spending time in class emphasizing that this is untrue!

 
 

• Sound travels better through solids and liquids than through air.
• Gravity in Space is Zero
• Ben Franklin's kite was struck by lightning
• Clouds, Fog, Shower-room mist are made of water vapor
• Air is weightless
• The North Pole of the Earth is in the North

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Closing

matthew.westra@mcckc.edu

Copyright © 1996 Matthew Westra
Critical Thinking Across the Curriculum Project
Longview Community College , Lee's Summit, Missouri - U.S.A.
One of the Metropolitan Community Colleges
"Where a Smart Future Begins"
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Inquiries to: michael.connelly@mcckc.edu

Last modified: 9/7/06