CHAPTER 1: THINKING

CRITICALLY WITH

PSYCHOLOGICAL SCIENCE

Introduction

Fact or Falsehood

1. Human intuition is remarkably accurate and free from error.

2. Most people seem to lack confidence in the accuracy of their beliefs.

3. Case studies are particularly useful because of the similarities we all share.

4. We tend to overestimate the number of people who share our attitudes and beliefs.

5. The opinions of 1500 randomly selected people can provide a very accurate picture of the opinions of an entire nation.

Fact or Falsehood

6. The scientific finding that children who watch violence on television tend to be violent proves that viewing violence causes it.

7. Listening to a tape with a subliminal message suggesting that you have a good memory can actually help improve your memory.

8. The purpose of the experiment is to re-create behaviors exactly as they occur in everyday life.

9. An analysis of the research indicates that psychologists have sometimes unnecessarily caused extreme pain to animals.

10. As a science, psychology is objective and value-free.

Fact or Falsehood

� Now at the top of your paper, predict how many

you think you got correct.

Fact or Falsehood

1. Human intuition is remarkable accurate and free from error.

2. Most people seem to lack confidence in the accuracy of their beliefs.

3. Case studies are particularly useful because of the similarities we all share.

4. We tend to overestimate the number of people who share our attitudes and beliefs.

5. The opinions of 1500 randomly selected people can provide a very accurate picture of the opinions of an entire nation.

False

False

False

True

True

Fact or Falsehood

6. The scientific finding that children who watch violence on television tend to be violent proves that viewing violence causes it.

7. Listening to a tape with a subliminal message suggesting that you have a good memory can actually help improve your memory.

8. The purpose of the experiment is to re-create behaviors exactly as they occur in everyday life.

9. An analysis of the research indicates that psychologists have sometimes unnecessarily caused extreme pain to animals.

10. As a science, psychology is objective and value-free.

False

False

False

False

False

Understanding Research

Discovering Psychology

Why do we have to learn this stuff?

Psychology is first and foremost a science.

Thus it is based in research.

Before we delve into how to do research, you should be aware of three hurdles that tend to skew our logic.

Hindsight Bias

� The tendency to believe, after learning the outcome, that you knew it all along.

I KNEW IT ALL ALONG

Overconfidence

• We tend to think we know more than we do.

• 82% of U.S. drivers consider themselves to be in the top 30% of their group in terms of safety.

• 81% of new business owners felt they had an excellent chance of their businesses succeeding. When asked about the success of their peers, the answer was only 39%. (Now that's overconfidence!!!)

Overconfidence

� Here are some examples of overconfidence among experts.

� There is no reason for anyone to have a computer in their home. (Ken Olsen, president of Digital Equipment Company, 1977)

� Heavier-than-air flying machines are impossible. (Lord Kelvin, British mathematician, physicist, and president of the British Royal Society, 1895)

� Wright Bros. December 17, 1903

� A severe depression like that of 1920-21 is outside the range of probability. (Harvard Economic Society, Weekly Letter, November 16, 1929)

� Stock Market Crash Oct 29, 1929 (Black Tuesday)

� Depression lasted almost a decade

� Man will never reach the moon, regardless of all future scientific advances. (Lee DeForest, inventor of the vacuum tube, 1957)

� July 20, 1969 one small step for man, one giant leap for mankind

� Nuclear powered vacuum cleaner will probably be a reality within 10 years. (Alex Lewyt, manufactures of vacuum cleaners, 1955)

Overconfidence

� Compare your score to your predicted score.

� By raise of hands, how many over predicted your

score?

� Overconfidence is a powerful phenomenon.

� Overconfidence stems partly from our tendency to

search for information that confirms our

preconceptions.

The Barnum Effect

� It is the tendency for people to accept very general or vague characterizations of themselves and take them to be accurate.

Impression of Psychology

With hopes of satisfying curiosity, many people listen to talk-radio counselors and psychics to

learn about others and themselves.

Dr. Crane (radio-shrink)

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Psychic (Ball gazing)

Demonstration

� Glass of water and paperclips.

� The limits of Intuition and Common Sense

� Counter to human intuition, water has a high surface

tension, behaving as though is has a flexible skin. That

skin pulls inward and resists breaking. The glass of

water will develop a great bulge before the water

flows over the edge.

Thinking Critically with Psychological Science

The Need for Psychological Science

� The limits of Intuition and Common Sense

� Many people believe that intuition and common sense are enough to bring forth answers regarding human nature.

� Intuition and common sense may aid queries, but they are not free of error.

� The Scientific Attitude

� The Scientific Method

Scientific Attitude

� How do we overcome the limits of our intuition,

hindsight bias, and overconfidence?

� The scientific attitude is composed of curiosity

(passion for exploration), skepticism (doubting

and questioning) and humility (ability to accept

responsibility when wrong).

Scientific Method

� Let’s take our chairs outside for a demonstration.

The Need for Psychological Science

� Critical Thinking

� thinking that does not

blindly accept

arguments and

conclusions

� examines assumptions

� discerns hidden values

� evaluates evidence

The Amazing Randi--Skeptic