Ib Psychology Course Book: Oxford Ib Diploma Programme [2 ed.] 0198398115, 9780198398110, 9780198398127

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for

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permission

International All

21,

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2017

of published

Vol.

Neurosurgery,

Psychosomatic

Theory

First

McCoy,

in

worldwide.

University

and

Springer.

M:

Neurology,

1998,

E

behavior

of reprinted

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Hamilton,

Kingdom

of Oxford

sociosexual

Behavior,

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211,

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2,

decisions

and

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General-Adaptation-Syndrome’

1951,

of

pp.

pp.

327-342,

http://www.annualreviews.org,

©

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reprinted

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Acknowledgements

author

and

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pigeon’,

Vol.

38

(2),

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pp.

of

168–172,

this

domain.

JM

and

Rubin,

Vol

ashbulb

DC:

‘Condence,

14,

5,

memories’,

SAGE

2003,

in

not

consistency,

Psychological

Journals.

Kingdom

World

The

public

in

1948,

origin. characterizes

Printed

Psychology,

environmental Talarico,

regulations

in

‘‘Superstition’

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Sniehotta,

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Health

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Health

Topics,

Health

Alan:

‘Exploring

Journal

of

the

central

Experimental

in

1996,

by

pp.

5-28,

Francis

reprinted

Ltd.,

by

permission

of

the

Health

publisher

(Taylor

Thinking

and

Deciding

(fourth

reprinted

we

University

Press,

GH,

in

all

Black,

JB

Cognitive

by

and

Turner,

Psychology,

TJ:

1979,

‘Scripts

Vol.

11,

in

permission

of

JD

&

Johnson,

1973,

by

W

G

MK:

Chase,

permission

Burbank,

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Aboriginal

Australia’,

p.

719,

in

Visual

K:

reprinted

of

‘Fighting

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and

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Bower,

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Jonathan:

Cambridge

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49A,

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Baron,

WHO,

permission.

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Promotion,

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Prevention Quarterly

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Contents

Introduction

........................................................

vi

The

influence

behaviour Unit

1

Research

Research

in

psychology ........................................

research:

the

Quantitative

experiment

research:

correlational

...............

2

Unit

9

Normality

5

Abnormal

versus

studies .......

20

Classification

Qualitative

research

...........................................

24

Prevalence

Qualitative

research

methods.............................

31

Validity

37

The

in

2

psychological

Biological

research .........................

and

role

of

approach

to

...................................................

used

to

behaviour ......................

study

the

for

to

behaviour

and

brain

Genes

and

..................................

78

87

Evolutionary

The

role

human

of

genetic

explanations

animal

behaviour

(HL

similarities..........

for

research

in

behaviour ........

94

108

Unit

6

3

Cognitive

Concepts

to

and

approach

principles

of

the

to

of

cognitive

Thinking

and

Reliability

of

115

Biases

in

and

Cognitive

only)

4

Cultural

norms

180

Social

origins

—cultural

The

digital

The

and

theory

individual

and

to

the

and

of

331

health

.............................................

339

2:

stress ...................................

344

350

of

human

relationships

discrimination............................

conflict

and

conflict

394

resolution ........

400

responsibility ..........................................

404

8

and

of

cultural

202

cognition

208

psychology

development ....................................

mind

Gender

220

of

empathy

and

446

455

peers

Effects

of

and

play ......................................

trauma

poverty

social

437

roles .......................

of

and

430

Attachment.......................................................

Role

identity

422

theory

............................................................

Childhood

group—social

group—social

Developmental

development ...........................................

Cognitive

and

on

464

resilience .....................

473

relationships ...................

481

identity Unit

theory

and

Development

attitudes,

...............................................

and

of

188

behaviour

......................................

the

explanations

world

approach

behaviour

dimensions

individual

cognitive

of

being

386

cognition.....................................

..............................................................

Cultural

and

370

Origins

individual

obesity

dynamics ...............................................

168

on

327

1:

......................................

decision-making ..........

behaviour—culture

health ....................................

psychology

relationships

Prejudice

........................................................

and

319

Psychology

160

influences

identities

......................

treatment

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problem

7

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memory ....................................

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of

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131

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306

313

in

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depression ...................

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health

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149

and

of

............

culture

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141

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theory

288

for

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269

.............

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behaviour ...............................

behaviour;

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56

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257

46

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behaviour

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clinical

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globalization

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methodology

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requirements

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488

v

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493

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evaluation .....................................

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resources ................................................

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495

analysis ...................................

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512

Index

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Athabasca University has a great learning resource on threats to internal validity. One tutorial consists

of two par ts, where par t 1 is the theoretical background and denitions and par t 2 is a practical

exercise involving the analysis of 36 hypothetical experiments.

If you want to practise identifying potential sources of bias in experiments, you can access the tutorial

here: https://psych.athabascau.ca/open/validity/index.php

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