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What Is Psychology?

What Is Psychology?

• Comes from Greek

psykhe logia +

“mind” “study of”

Defining Our Terms

DEFINITION

• The scientific study of behavior and mental processes

Science

way of getting knowledge about

the world based on observation and reason

PUBLIC PRIVATE

Mental processes

all the things we can

do with our minds

Behavior

observable action

Four Recurring Themes

in Psychology

A. Action-oriented quality of research and

practice

B. Relationship between brain and behavior

C. Nature and nurture

D. Range of human diversity

Why Psychology Is a Science

Three scientific principles

1. Objectivity

• Evaluating research and theory on their

own merits

2. Systematicity

• Having a plan for gathering data

3. Healthy Skepticism

• Confirming findings through repeated

observations

Research Methods in Psychology

The Scientific Method

1. State the problem

2. Develop a hypothesis

3. Design a study

4. Collect and analyze data

5. Draw conclusions, report results

Research Methods in Psychology

A. The Experimental Method

– Systematically manipulating variables and

observing the elements of a situation

• Can show cause and effect relationship

The Experimental Method

• Two types of variables:

– Independent variable (IV)

• Intentionally manipulated by experimenter

– Dependent variable (DV)

• Behavior or response that is expected to change because of IV

• Outcome that depends on IV

Population Sample

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The Experimental Method

• Sample

– Large enough

– Random

– Representative of population

• Operational Definition

– How will the variable(s) be measured?

• Participants in study must be alike on all variables except the IV

• Participants randomly assigned to groups

– Experimental group receives treatment

– Control group does not receive treatment

The Experimental Method

Experimental Group

– Uses device within

30 min. of bedtime (IV)

– Measure

# hours sleep (DV)

Control Group

– No device (IV)

– Measure

# hours sleep (DV)

What are the effects of pre-bedtime screen exposure on sleep?

Compare these!

Are they significantly different?

The Experimental Method

• If groups are significantly different, you can

conclude that manipulation caused

experiment’s effects

– This means statistical difference, i.e.,

difference can’t be explained by chance

• If groups are not significantly different,

extraneous variables may have “confounded

the results”

Other Research Methods

B. Descriptive Methods

Describe relationships and events

Do not manipulate variables

Therefore, CAN’T make inferences

about cause and effect

Five types

Descriptive Methods

1. Case studies

– Intensive study of one case (individual)

2. Naturalistic Observation

– Observation of behavior in a naturally

occurring situation

3. Surveys

– Interviews and questionnaires

– Sample must be representative

Descriptive Methods

4. Correlational studies

– Establish relationships between two

variables

– Because variables are not controlled, can

NOT infer causation

– CORRELATION ≠ CAUSATION!

Descriptive Methods

5. Ex Post Facto Studies

(a.k.a. “Quasi-Experimental”)

– Describe differences between groups of

participants that differ naturally on a

variable such as race or gender

• Subject variable

– Variable is NOT manipulated, so these

are not true experiments

How Do Psychologists

Evaluate Research Findings?

• A. Using statistics

– Statistics is a branch of mathematics that

deals with classifying and analyzing data

– Psychologists use two types:

1. Descriptive

2. Inferential

A. Using Statistics

1. Descriptive Statistics

Average i. Mean

ii. Median

iii. Mode

Middle Score

Most common score

a. Measures of Central Tendency

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1. Descriptive Statistics

• b. Measures of Variability

ii. Standard

Deviation

(SD)

• How much do the scores vary,

on average, from the mean?

(x - x)2

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i. Range • Highest minus lowest score

1. Descriptive Statistics

c. Correlation Coefficients

• Numerical way to describe relationship between two variables

• Ranges from –1 to +1 (expressed as r)

• Positive correlation coefficients indicate that

– As one variable increases, the other increases

– As one variable decreases, the other decreases

c. Correlation Coefficients

• Negative correlation coefficients indicate that

– As one variable increases,

the other decreases

• Closer to |1| (-1 or +1), the stronger the

relationship

• Closer to 0, the weaker the relationship

c. Correlation Coefficients

r = +1.0 Strong, positive correlation

r = -.95 Strong, negative correlation

r = -.33 Moderate, negative correlation

What kind of relationship does this graph show?

Types of Correlations

negative correlation

What kind of relationship does this graph show?

Types of Correlations

no relationship

What kind of relationship does this graph show?

Types of Correlations

positive correlation

Class Data

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Class Data Class Data Class Data

• Relatively strong correlations

.610 – pieces gum chewed & minutes getting

ready

.597 – pairs shoes & times tardy

Class Data

• Relatively weak correlations

.0022 – Dunkin Donuts & time getting ready

.0023 – Facebook friends and TV hours

-.0033 – texts & housemates

A. Using Statistics

2. Inferential Statistics

• Used to determine if research results are

significant

• Significant differences are statistically

unlikely to occur because of chance

alone

Expectancy Effects

• Expectations of researcher and participants can influence outcome of study

• We control for these effects with the experimental design

• Examples:

1. Self-fulfilling prophecy

2. Placebo effect

3. Hawthorne effect

Expecatancy Effects

1. Self-fulfilling prophecy – Researchers’ expectations unknowingly

create situation that affects results

2. Placebo effect – Even when not given IV (treatment),

participant’s expectations can make them respond as if they HAVE been given IV!

How can we control for these two effects?

Expectancy Effects

• Double-blind Technique

–Neither researcher nor participants know

which group (experimental/control)

participants have been assigned to

–Done as often as possible in psychology

–Must be done in ANY research on medical

treatments

Some Correlations…

• These correlation coefficients are real (really)

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Some Correlations… Some Correlations… Do you think these correlations

mean anything?

• Spurious correlation

– When two unrelated variables appear to be

connected

Ethical Principles

• Rules concerning research conduct

• For human participants:

– Informed consent

– Can’t be coerced

– Can drop out at any time

– Confidentiality

STATEMENT OF RIGHTS

In order to ensure that all of our volunteers understand the nature and

circumstances of psychological research, we have prepared the following

remarks.

First, we would like to remind you that participating in this, and all other

experiments, is entirely voluntary. Presumably, you have already agreed to

participate or you would not be reading this statement, but this agreement does

not bind you in any way. The experimenter will explain the procedures of the

experiment to you in a moment, and if upon hearing more about the experiment

you would prefer not to participate, that will be quite all right. Furthermore, if at

any time during the experiment you would prefer not to continue, for any

reason, you should feel quite free to so inform the experimenter and leave. We

hope, of course, that you will be able to help us in this study and can assure you

that no offense, injury, or intrusion of privacy is intended in this experiment. We

think that, in fact, you will find the procedures innocuous, and perhaps enjoyable.

As you are probably aware, psychologists usually feel that it is necessary that

volunteers not be informed about all of the details of an experiment, because if

volunteers knew, for instance what the experimenter’s expectations were, they

would not be able to react in a natural way. Hence, as in most experiments, in

this experiment we will not be able to describe in detail all of our rationale,

expectations, and hypotheses. However, so that you can make an informed

judgement as to whether you wish to participate, we will describe all of the

actual procedures, and at the conclusion of the experiment we will be happy to

explain everything, and answer any questions you have.

Signature

Ethical Principles

• Debriefing

– Explain study when done

• Deception

– Can only be used if justified by its scientific, educational, or practical

History of Psychology

• Interest goes back

thousands of years

• Emphasis on

supernatural

• Skulls from 6500BC

have holes drilled to

release “evil spirits”

History of Psychology

• Ancient cultures

–Dreams sent by gods as reward or

punishment

–Gods told them when to harvest or go

to war

• 6th Century B.C.

–Writers in India, China, and Greece

first talked about “the mind”

Roots in Philosophy • Greeks

– Socrates

• “Know thyself”

– Aristotle

• Peri Psyches (About the

Mind)

– Hippocrates

• Abnormal behavior

caused by abnormal

brain

Socrates

Aristotle

Hippocrates

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Roots in Philosophy

Pre-scientific Psychology

Do you have a soul?

Is the mind connected to the body or

separate?

Are ideas inborn or is the mind a

“blank slate” filled by experience?

Psychological Science Is Born

The Enlightenment

17th and 18th centuries

Empiricism

•Knowledge comes from

experience via the senses

John Locke idea of

tabula rasa (“blank slate”)

History of Psychology

• 17th Century: Scientific

Revolution

– Focus on

observations, not

superstitions

• 19th: Phrenology

– Examining shape of

head or skull could

reveal mental abilities A phrenology map, show where

certain traits are “located”

History of Psychology • 1879: Leipzig, Germany

– Wilhelm Wundt (1832-1920) opened

first lab for scientific study of mental

processes

– Moved psychology from philosophy to

science

Wundt Wundt in lab with colleagues

Early Approaches to Psychology

Structuralism

• Edward Titchener (British)

• Used introspection to study structure of the mind

– Sensation, emotion, ideas

• Consciousness = sum of all mental experience at one time

(1867-1927)

Early Approaches to Psychology

• Functionalism

–William James

–Studied how the

mind used its

abilities to

function in

environment

(1842 – 1910)

Early Approaches to Psychology

• Psychoanalysis

– Sigmund Freud

– Unconscious conflicts

influence behavior

– Sex and aggression are

important drives

(1856-1939)

Early Approaches to Psychology

• Gestalt Psychology

– Max Wertheimer,

Kurt Koffka, Wolfgang

Köhler

– Studied the person’s

whole experience, not

just pieces of it

(1880-1943)

Early Approaches to Psychology

• Behaviorism

– John B. Watson

–Psychology must be

defined as the study

of observable

behavior only

(1878-1958)

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Early Approaches to Psychology

• Behaviorism

– B.F. Skinner

– Influenced by Watson

– All behavior is based on rewards and punishments

– Seen by many as most influential psychologist ever

(1904-1990)

Challenges to Behaviorism

Humanistic Psychology

– Free will, self-determination, basic goodness of

people

Abraham Maslow

(1908-1970)

Carl Rogers

(1902-1987)

The Cognitive Revolution

of the 1960s

• Cognitive Psychology

– The study of mental processes:

Thoughts

Learning

Emotions

Memory

Decision making

New Directions in Psychology:

Evolutionary Psychology

• Based on work of Charles Darwin

• Argues that humans have evolved

both physically and psychologically

• Adaptive behaviors passed on to

future generations through

natural selection

(1809-1882)

What Psychologists Do

• Psychology is 2nd most popular major

• 120,000 psychologists in U.S.

• You must have a “graduate degree”

(e.g., Masters, Ph.D.)

What Psychologists Do

• Three main fields

1. Human services

2. Applied psychology

3. Research psychology

What Psychologists Do

• Human Services

– Involves helping people with mental

health problems

Human Services:

Clinical Psychologist

• Most common Ph.D. in psych

• Greatest career options

• Very competitive

• Serious mental illness

• Psychological testing,

psychotherapy, research

• Work in private practice,

hospitals, colleges

Human Services:

Counseling Psychologist

• Usually deal with “day to day” problems (i.e., adjustment problems)

• Typical problems involve relationships, like marriage and family problems, parenting, etc.

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Human Services:

Psychiatrist

• A medical doctor (M.D.) who specializes

in mental disorders

• Tend to focus on the biological causes of

mental problems

• Many use psychiatric medications to treat

disorders

Human Services:

School Psychologist

• Focus on problems

that interfere with

learning

• Give tests to identify

learning disabilities

Applied Psychology

• Using psychology to solve problems in real

world situations

Applied Psychology:

Sports Psychologist

• Tries to understand and improve

sports performance

• Topics of interest:

– Relaxation

– Visualization

– Coaching styles

– Exercise and mental health

Applied Psychology:

Forensic Psychologist

• Work within legal

system

– Police selection

– Study eyewitness

testimony

– Expert witnesses in

insanity trials

Research Psychology

• Interested in

studying basic

research issues, not

necessarily applying

them

Research Psychology

• Developmental Psychologist

– Studies how people change throughout the life span

• Cognitive Psychologist

– Studies mental processes such as memory, perception, and learning

• Social Psychologist

– Studies how an individual is affected by other people, and how people interact