Chapter 1: Thinking critically with

psychological sciencepsychological science

Introduction

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 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.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

False

False

False3. 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

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.

False

Falsehelp 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

Understanding Research

DISCOVERING PSYCHOLOGY

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 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.

The Need for Psychological Science

• Psychologists, like all scientists, use the scientific

method to construct theories that organize

observations and imply testable hypotheses

– Hindsight Bias– Hindsight Bias

– Overconfidence

Hindsight Bias

• Hindsight bias: the tendency to exaggerate one’s ability to have foreseen how something would turn out after learning the outcome.

• After the horror of 9/11 it seemed obvious the American intelligence services should have taken American intelligence services should have taken advanced warnings more seriously, that airport security should have anticipated box-cutter-wielding terrorists, that occupants of the second tower should have known to play it safe and leave. With 20/20 hindsight, everything seems obvious.

Overconfidence

• Compare your score to your predicted score.

– By raise of hands, how many over predicted your score?

• Overconfidence is the tendency to overestimate the accuracy of our current

• Overconfidence is the tendency to overestimate the accuracy of our current

knowledge and is a powerful phenomenon.

• Overconfidence stems partly from our tendency to search for information that confirms our preconceptions.

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)

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

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

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

Scientific Attitude

• How do we overcome the limits of our

intuition, hindsight bias, and overconfidence?

• Critical Thinking

– Thinking that does not blindly accept arguments – Thinking that does not blindly accept arguments

or conclusions but questions their validity

The Need for Psychological Science

� Critical Thinking

� thinking that does not

blindly accept blindly accept

arguments and

conclusions

� examines assumptions

� discerns hidden values

� evaluates evidenceThe Amazing Randi--Skeptic

Ch 1: thinking critically with

psychological sciencepsychological science

Research Methods

The Need for Psychological Science

� Theory

� an explanation using an integrated set of

principles that organizes and predicts

observationsobservations

� Hypothesis

� a testable prediction

� often implied by a theory

The Need for Psychological Science

The Need for Psychological Science

� Operational Definition

� a statement of procedures (operations) used to

define research variables

� Example-

� intelligence may be operationally defined as what

an intelligence test measures

Scientific Method

• Technique using tools such as observation,

experimentation, and statistical analysis to

learn about the world

• Through its use, psychology is thereby • Through its use, psychology is thereby

considered a science.

Research and Research Methodology

• Method of asking questions then drawing

logical supported conclusions

• Researchers need to be able to determine if

conclusions are reasonable or not (critical conclusions are reasonable or not (critical

thinking).

Bias

• Situation in which a factor unfairly increases

the likelihood of a researcher reaching a

particular conclusion

• Bias should be minimized as much as possible • Bias should be minimized as much as possible

in research

Researcher Bias

• The tendency to notice evidence which

supports one particular point of view or

hypothesis

• Objectivity tends to reduce bias.• Objectivity tends to reduce bias.

Participant Bias

• Tendency of research subjects to respond in certain ways because they know they are being observed

• The subjects might try to behave in ways they • The subjects might try to behave in ways they believe the researcher wants them to behave

• Can be reduced by naturalistic observation

Description

Psychologists describe behavior

using case studies, surveys, and using case studies, surveys, and

naturalistic observation

Case Study

� Psychologists

study one or more

individuals in great

depth in the hope depth in the hope

of revealing things

true of us all

Is language uniquely human?

Uses for Case Studies

• Source of insights and ideas– Particularly useful in early stages of investigation a

specific topic

– Freud and others theories emerged from case studies

• Used to describe particularly rare phenomena• Used to describe particularly rare phenomena– Ex: The study of presidential assassins

• Form of psychobiography's involve the application of psychological concepts and theories in an effort to understand the lives of famous people– Martin Luther, da Vinci, etc

• Used to provide concreted examples of abstract concepts and processes

Limitations in Case Studies

• This technique is very open to bias

– Observations done by single investigator

– No way of assessing reliability or validity

• Difficulty of applying data from one person to everyone

• Useless in providing evidence to test behavioral

theories or treatments

– The lives and events studied occur in uncontrolled

fashion and without comparison information.

– No matter how reasonable the investigator’s

explanations, alternative explanations cannout be ruled

out.

Surveys

• Research method that relies on self-reports;

uses surveys, questionnaires, interviews.

• Usually a very efficient and inexpensive

methodmethod

Wording of Survey Questions

• Pass out surveys

• By raise of hands, how many estimated

greater than 1500 miles?

• Greater than 30 million people?• Greater than 30 million people?

– Actual answers: 2348 miles and 36 million

• Respondents may be ignorant to wording

– Ex: 77% of people were interested in plants and

trees, but only 39% were interested in botany.