Individual Differences and Personality

How do we come to be who we are? Why do we differ in our personalities? How do these differences matter in life? Individual Differences and Personality aims to describe how and why personality varies among people. Unlike books that focus on individual theorists, this book focuses on current research and theory on the nature of personality and related individual differences. The book begins by discussing how personality is measured, the concept of a personality trait, and the basic dimensions of personality. This leads to a discussion of the origins of personality, with descriptions of its developmental course, its biological causes, its genetic and environmental influences, and its evolutionary function. The concept of a personality disorder is then described, followed by a discussion of the influence of personality on life outcomes in relationships, work, and health. Finally, the book examines the important differences between individuals in the realms of mental abilities, of beliefs and attitudes, and of behavior.

• Presents a scientific approach to personality and related individual differences, as well as theory and research on the fundamental questions about human psychological variation
• New edition presents findings from dozens of new research studies of the past six years
• Includes new chapter on vocational interests and a revised chapter on personality disorders reflecting DSM-5 formulation
• Contains streamlined descriptions of measurement concepts and heritability research
• Includes various boxes containing interesting asides that help to maintain the student’s attention

Undergraduate and graduate level courses in personality

Acknowledgments

Preface

Introduction

The Study of Personality

The Universal, the Unique, and the In-Between

Idiographic Versus Nomothetic Approaches

Outline of this Book

Chapter 1. Basic Concepts in Psychological Measurement

1.1 Some Simple Statistical Ideas

1.2 Assessing Quality of Measurement: Reliability and Validity

1.3 Methods of Measurement: Self- and Observer Reports, Direct Observations, Biodata

1.4 Summary and Conclusions

Chapter 2. Personality Traits and the Inventories that Measure Them

2.1 The Idea of a Personality Trait

2.2 Personality Traits and Other Psychological Characteristics

2.3 Do Personality Traits Exist?

2.4 Measuring Traits by Self- or Observer Report: Structured Personality Inventories

2.5 Strategies of Personality Inventory Construction

2.6 Self- and Observer Reports on Personality Inventory Scales

2.7 Summary and Conclusions

Chapter 3. Personality Structure: Classifying Traits

3.1 Which Traits to Measure? Completeness without Redundancy

3.2 A Gentle Introduction to Factor Analysis

3.3 Factor Analysis of Personality Traits: How to Find a Representative Set of Traits?

3.4 Lexical Studies in the English Language: The Big Five Personality Factors

3.5 Lexical Studies in Many Languages: The HEXACO Personality Factors

3.6 What it all Means: A Few Dimensions, but Many Personalities

3.7 Summary and Conclusions

Chapter 4. Developmental Change and Stability of Personality

4.1 Defining Change and Stability

4.2 Developmental Changes in Mean Levels of Personality Traits

4.3 Stability of Traits Across the Years (and the Life Span)

4.4 Personality in Childhood and Infancy: Measurement and Structure

4.5 Summary and Conclusions

Chapter 5. Biological Bases of Personality

5.1 Early Ideas: The Four “Humors” and Personality

5.2 Neurotransmitters

5.3 Brain Structures

5.4 Hormones

5.5 Summary and Conclusions

Chapter 6. Genetic and Environmental Influences on Personality

6.1 The Question: Nature versus Nurture

6.2 Examining the Similarity of Relatives

6.3 Separating Heredity and Environment

6.4 The Answers

6.5 Assumptions Underlying Heritability Studies in General

6.6 Assumptions Underlying Twin-Based Heritability Studies in Particular

6.7 Effects of the Unique Environment on Personality? Parental Treatment, Peer Groups, and Birth Order

6.8 Summary and Conclusions

6.9 Appendix: Difficulties in Separating the Effects of Heredity and Environment

Chapter 7. The Evolutionary Function of Personality

7.1 The Idea of Evolution by Natural Selection

7.2 Why Are We Not All the Same? Fluctuating Optimum and Frequency Dependence

7.3 Adaptive Trade-offs between High and Low Levels of the HEXACO Personality Factors

7.4 The Operation of the Fluctuating Optimum and Frequency Dependence: Some Examples

7.5 Summary and Conclusions

Chapter 8. Personality Disorders

8.1 The Idea of a Personality Disorder

8.2 The DSM-5 Personality Disorders

8.3 An Alternative System for Personality Disorders

8.4 Origins of Personality Disorders: Developmental Change and Stability, Biological Bases, Heredity and Environment, and Evolution

8.5 Treatment of Personality Disorders

8.6 Summary and Conclusions

Chapter 9. Personality and Life Outcomes

9.1 Does Personality Predict Features of One’s Life Story?

9.2 Relationships and Marriage

9.3 Friendships and Other Peer Relationships

9.4 Health-Related Outcomes

9.5 Academic Performance

9.6 Job Performance

9.7 Law-Abidingness versus Criminality

9.8 Life Satisfaction

9.9 Summary and Conclusions

Chapter 10. Mental Ability

10.1 The Domain of Mental Ability

10.2 The Structure of Mental Ability: One Dimension or Many?

10.3 Developmental Change and Stability in Mental Abilities

10.4 Biological Bases of Mental Ability

10.5 Genetic and Environmental Influences on Mental Ability

10.6 Evolutionary Function of Mental Ability

10.7 Mental Ability and Life Outcomes

10.8 Not All g-Loaded Tasks are the Same

10.9 Alternative Ideas About Mental Abilities

10.10 Summary and Conclusions

Chapter 11. Vocational Interests

11.1 How Vocational Interests are Measured

11.2 Score Reports from Vocational Interest Surveys

11.3 Constructing Vocational Interest Scales: Empirical and Rational Strategies

11.4 Major Dimensions of Vocational Interests

11.5 Vocational Interests and Personality

11.6 Vocational Interests and Mental Abilities

11.7 Validity of Vocational Interest Surveys

11.8 Origins of Vocational Interests: Developmental Change and Stability, Genetic and Environmental Influences, Biological Bases, and Evolution

11.9 Summary and Conclusions

Chapter 12. Religion and Politics

12.1 Religion

12.2 Politics

12.3 Origins of Religious Beliefs and Political Attitudes: Biological Bases, Genetic and Environmental Influences, and Evolutionary Function

12.4 Summary and Conclusions

Chapter 13. Sexuality

13.1 Major Dimensions of Sexuality

13.2 Sexuality and Personality

13.3 Origins of Variation in Sexuality: Developmental Stability and Change, Genetic and Environmental Influences, Biological Bases, and Evolution

13.4 Sexual Arousal

13.5 Sexual Commitment (or Restricted versus Unrestricted Sociosexuality)

13.6 Sexual Orientation

13.7 Summary and Conclusions

Conclusions

What We Have Learned So Far

What We Have Yet to Learn

Final Remarks

References

Index