chapter 4: the role of chance and coincidence

Chapter 4: The Role of Chance and CoincidenceChapter 5: Seeing What is Not There

Chapter 6: Seeing Associations That Aren’t There

Chapter 4: The Role of Chance and Coincidence

People have a tendency to try to make connections between things, even if they are not related.

Examples: flipping coins, roulette wheels, the hot hand in basketball, superstitions.


Coincidences:

Carl Jung (1875-1961) thought that they were evidence of synchronicity, the attempt to impose meaning on the world

by some mysterious force.


Coincidences:

Kida: If there is a simpler explanation, we should prefer it (Ockham’s razor). Given the bell curve, highly improbable

events will occur sometimes.


Coincidences:

Question: But is everything a coincidence? Are there some occasions on which things happen for a reason? How

would you decide this question using reasons and logic?


Coincidences:

Ockham himself believed in God. If there is a God, some things that appear to be coincidences might not be. Does Kida want to say that belief in God is just superstition? Is

that fair?

Chapter 5: Seeing Things that Aren’t There

Perception is not just a passive process of receiving data – it involves judgment.

Our expectations can influence what we perceive:

http://www.youtube.com/watch?v=G-lN8vWm3m0



Our desires can also influence what we perceive:

“I can change my partner.”

Presidential debate results.



Our brains are complicated structures, and they piece together a picture of reality in the most efficient way that

they can, but they are not perfect processors of information:

http://boingboing.net/2012/05/22/weird-illusion-causes-faces-to.html


However, we also perceive a great deal of things in a quick period, without realizing it.


By ranking attractiveness based on T shirt smell alone, women reliably chose men whose immune systems would

complement their own, leading to healthier offspring.

http://www.pbs.org/wgbh/evolution/library/01/6/l_016_08.html


Researchers discovered that it takes about a tenth of a second to form an impression of the attractiveness of

another human face.

http://www.psychologicalscience.org/index.php/publications/observer/2006/july-06/how-many-seconds-to-a-first-impression.html




Chapter 6: Seeing Associations that Aren’t There

We always look for patterns, even if none exist:

Stock market pricesRorschach blots


We tend to ignore negative instances:

Sugar Consumption:

Yes No

Hyperactivity: Yes 250 50

No 50 10


Correlation does not always prove causation

Sometimes two variables are correlated, but it is just a coincidence:

The Redskins Rule: if the Redskins win the last home game before a Presidential election, the incumbent party will win it; and if the Redskins lose their last home game before the election, there will be a change of political party. (This was

true from 1940 until the end of the 20th century.)



Sometimes two variables are correlated, but the order of causation is actually reversed:

Studies show that people who are terminally ill are unhappy, so unhappiness contributes to terminal illness.



Sometimes two variables are correlated, but they do not cause one another because a third variable causes them both:

I get a fever and a headache, so I conclude that the fever causes the headache, but that’s not true – they are both

caused by a virus.


Selection Bias

One’s choice of a sample is sometimes not representative of the population as a whole.

If I survey people about prayer in the schools and find that 85% favor this, I might conclude that most people favor it, but if all of my surveys take place outside of the church, this is a biased

sample

Argument Practice

The more I run, the more endurance I have, so the increased running must account for my increased endurance.

Argument Practice

The CD left on the dashboard of the car melted in the sun, whereas the CD left under the seat was just fine. So being in the sun must have melted the CD.

Argument Practice

Whenever Bill gets anxious, he has an exam. So Bill's anxiety must cause his teachers to give exams.

Argument Practice

There are two cats in the house, but only one of them has fleas. The other one is wearing a flea collar, so the collar must prevent that cat from getting fleas.

Argument Practice

Statistics indicate a striking correlation: whenever the Raiders play on Monday Night Football against the Chiefs and there is a full moon, the Raiders win. Hence the full moon must have something to do with the success of the Raiders.

Argument Practice

My phone rings whenever the light on the phone blinks, so this blinking light must cause the ringing to occur.

Argument Practice

The more she practices playing the violin, the better she gets, so practicing must make her better.

Argument Practice

Before going on stage, I get sweaty palms and butterflies in my stomach. Since these two things always happen together, I think that the sweaty palms cause the butterflies in my stomach, so I'm going to have my sweat glands rendered inactive with laser therapy (in order to prevent those bothersome butterflies in my stomach).

Argument Practice

Our old tent, made of red plastic, did not attract any insects, but our new tent, made of blue canvas rubbed in beeswax, does attract bugs. So the bugs like the blue color.

Argument Practice

I have ten students doing well in my class and twelve students doing poorly. The ten students doing well all have good GPAs, so a good GPA must make them do well in my class.

Argument Practice

My furnace always squeaked when the fan was on until I changed the belt. Now it works without squeaking, so the old belt must have caused the squeaking.

Argument Practice

There is a correlation between muggers pointing guns at people and people being afraid. The sensible conclusion seems to be that when people are afraid, this makes muggers point guns at them.

Argument Practice

It is bad luck to walk under a ladder. Every time I do it, something bad happens to me that day or soon thereafter.

Argument Practice

Since the only difference between Mary and I was that she studied for this exam and I didn't (and she passed and I failed), this must explain the difference in our grades.

Argument Practice

I've noticed that whenever that darn smoke alarm starts screaming, the house is full of smoke. So the screaming of the alarm must fill the house with smoke. We should get it fixed.

chapter 4: the role of chance and coincidence

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