Personality and Disease: Scientific Proof vs. Wishful Thinking

A tremendous amount of research has been performed looking at the relationship between personality and disease. Research on this topic has been spread throughout scientific journals on psychology, behavioral health, psychoneuroimmunology, oncology, and epidemiology. Personality and Disease brings this research together in one place for the first time.

With contributions from world experts, the book summarizes research findings on personality as it relates to cancer, heart disease, diabetes, asthma and allergies, dementia, and more. Is there such a thing as a cancer- prone personality? Do sadness, anger, stress, or shyness affect the likelihood that we will fall ill to specific diseases? Can we protect ourselves from disease through a positive outlook?

This book will address both what we know, and what we persist in believing despite evidence to the contrary, and why such beliefs persist in the face of evidence.

• Investigates whether and how personality affects disease generally
• Includes cancer, heart disease, diabetes, asthma, allergies, and dementia
• Separates fact from fiction, evidence from beliefs
• Collates research from a wide variety of scientific domains
• Contains international perspectives from top scholars

• Language: English
• Publisher: Academic Press
• Release date: Jun 29, 2018
• ISBN: 9780128054451

Book preview

Personality and Disease

Scientific Proof vs. Wishful Thinking

Editor

Christoffer Johansen

Table of Contents

Cover image

Title page

Copyright

List of Contributors

About the Editor

Preface

Chapter 1. A Brief Historical Overview on Links Between Personality and Health

A Brief Historical Overview on (Assumed) Links Between Personality and Health

Current Models of Links Between Personality and Health: (Basic) Personality Traits

Other Personality Constructs Linked to Health

Summing-Up

Chapter 2. How to Measure the Personality

Introduction

Psychometrics

From Psychometrics to Clinimetrics

The Scalability of Eysenck’s Neuroticism Scale

The Scalability of Eysenck’s Extraversion/Introversion Scale

The Scalability of Eysenck’s Psychoticism Scale

Distinguishing Between Traits and States

Other Attempts to Describe Personality Traits

Item Banks

Conclusion

Chapter 3. Personality as Determinant of Smoking, Alcohol Consumption, Physical Activity, and Diet Preferences

Introduction

Smoking

Alcohol Consumption

Physical Activity

Diet Preferences

Mechanisms Explaining the Association Between Personality and Health Behaviors

Conclusion

Chapter 4. Personality and Cardiovascular Disease

Introduction

Cardiovascular Disease

Personality

Potential Mechanisms

Reviewing the Evidence

Discussion

Conclusions

Public Health Implications

Chapter 5. Personality and Type 2 Diabetes: An Overview of the Epidemiological Evidence

Introduction

The Big Five Personality Traits

Plausible Mechanisms Linking Personality to Increased Risk of Developing Diabetes

The Influence of Personality on Diabetes Risk: Metaanalyses of Individual-Participant Data for Personality as a Risk Factor for Incidence Diabetes

The Influence of Chronic Disease on Personality: Evidence for Type 2 Diabetes as a Risk Factor for Changes in Personality

Conclusions and Practical Implications

Chapter 6. Personality and Dementia: Personality as Risk Factor or as Early Manifestation in Dementing Disorders?

Personality Alterations in Dementia

Personality as a Risk Factor for Dementia

Discussion

Personality Changes as a Direct Result of the Disease

Personality Changes as a Risk Factor for the Development of Dementia

Methodological Limitations of Personality Research in Dementia

Conclusion

Chapter 7. Personality, Asthma, and Allergies

Introduction

Biopsychosocial Medicine

Placebo Effects and Real Treatments

Randomized, Double-Blind Control Trials

Personality and Illness

Asthma

Allergies

Conclusion

Chapter 8. The Personality and Risk for Cancer

What Is a Risk Factor for Cancer?

Mechanisms

Chapter 9. Personality and Social Relationships: As Thick as Thieves

A Taxonomy of Social Relationships

Conceptions of Personality

Personality as a System Within Systems

My Partner and Me: Personality and Partner Relationships

My Friends and Me: Personality and Friendships

Interim Conclusion: What Does All This Mean and How Does It Relate to Health?

Adding Another Level of Complexity: The Role of Life Transitions

Future Directions and Open Questions

Conclusion

Chapter 10. Personality Genetics

Introduction

Estimating Heritability

Identifying Genes

The Relationship Between Personality and Health

Issues of Complexity

Chapter 11. The Enduring Appeal of Psychosocial Explanations of Physical Illness

Research in the Mind, Body, and Health Before World War II

The Bridge Between the Mind and Body: The Idea of Stress

Risk, Lifestyle, and the Diseases of Modernity

Stress, Health, and Personality

Preventative Medicine

The Seductive Power of Personality as an Explanation of Disease

Conclusion

Chapter 12. What Mechanisms Explain the Links Between Personality and Health?

Mechanisms Linking Personality and Health

Selected Illustrations of Mechanisms Linking Personality and Health

Concluding Thoughts

Index

Copyright

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Notices

Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

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A catalogue record for this book is available from the British Library

ISBN: 978-0-12-805300-3

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Publisher: Nikki Levy

Acquisition Editor: Nikki Levy

Editorial Project Manager: Barbara Makinster

Production Project Manager: Anusha Sambamoorthy

Cover Designer: Matthew Limbert

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List of Contributors

G. David Batty,     Department of Epidemiology and Public Health, University College London, London, United Kingdom

Per Bech,     Psychiatric Research Unit, Mental Health Centre North Zealand, University of Copenhagen, Hillerød, Denmark

Pernille E. Bidstrup,     Cancer Survivorship Unit, Danish Cancer Society Research Center, Copenhagen, Denmark

Roderick D. Buchanan,     History and Philosophy of Science Program, School of Historical and Philosophical Studies, University of Melbourne, Melbourne, VIC, Australia

Helen Cheng

Department of Psychology, University College London, London, United Kingdom

ESRC Centre for Learning and Life Chances in Knowledge Economies and Societies, Institute of Education, University College London, London, United Kingdom

Jesper Dammeyer,     Department of Psychology, University of Copenhagen, Copenhagen, Denmark

Jaime Derringer,     Assistant Professor of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, United States

Adrian Furnham

Department of Psychology, University College London, London, United Kingdom

Norwegian Business School, Olso, Norway

Christian Hakulinen,     Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland

Nick Haslam,     Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia

Bertus F. Jeronimus

University of Groningen, Department of Developmental Psychology, Groningen, The Netherlands

University of Groningen, University Medical Center Groningen, Department of Psychiatry, Interdisciplinary Center Psychopathology and Emotion regulation (ICPE), Groningen, The Netherlands

Christoffer Johansen

Oncology Clinic, Finsen Center, Rigshospitalet, Copenhagen, Denmark

The Danish Cancer Society Research Center, Copenhagen, Denmark

Lena Johansson,     Neuropsychiatric Epidemiology Unit, Sahlgrenska Academy, Centre for Ageing and Health (AgeCap) at the University of Gothenburg, Gothenburg, Sweden

Markus Jokela,     Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland

Mika Kivimäki

Department of Epidemiology and Public Health, University College London, London, United Kingdom

Clinicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland

Marcus Mund,     Friedrich-Schiller-Universität Jena, Department of Personality Psychology and Psychological Assessment Germany, Jena, Germany

Franz J. Neyer,     Friedrich-Schiller-Universität Jena, Department of Personality Psychology and Psychological Assessment Germany, Jena, Germany

Wade Pickren,     Center for Faculty Excellence, Ithaca College, Ithaca, NY, United States

Maria D. Ramirez Loyola,     Psychological Sciences and the Health Sciences Research Institute, University of California, Merced, CA, United States

Lianne M. Reus,     Department of Neurology and Alzheimer Centre, VU University Medical Centre, Amsterdam, The Netherlands

Anna Song,     Psychological Sciences and the Health Sciences Research Institute, University of California, Merced, CA, United States

Ivalu K. Sørensen,     National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark

Pieter J. Visser

Department of Neurology and Alzheimer Centre, VU University Medical Centre, Amsterdam, The Netherlands

Department of Psychiatry, Maastricht University, Maastricht, The Netherlands

Deborah J. Wiebe,     Psychological Sciences and the Health Sciences Research Institute, University of California, Merced, CA, United States

Emil Wolsk,     Department of Cardiology, Rigshospitalet, Copenhagen, Denmark

Ingo Zettler,     Department of Psychology, University of Copenhagen, Copenhagen, Denmark

About the Editor

Christoffer Johansen is a professor in the oncology clinic at Rigshospitalet, Copenhagen, and is responsible for the first Psychosocial Cancer Research Unit at the Institute of Cancer Epidemiology with the Danish Cancer Society (EPI). He has 450+ peer-reviewed publications and 4 published books on cancer, with an h factor of 60. He holds several editor positions in cancer survivorship journals, is past president of The International Society of Psycho-Oncology, and has served on scientific advisory boards for The Netherlands Cancer Institute, The Karolinska Institute, and The Hamburg Cancer Research Center, Eppendorf. He additionally has been a senior advisor to the Danish National Board of Health. In his scientific career, Christoffer Johansen received and managed grants for more than 25 million dollars.

Dr. Johansen received his MD in 1986, his PhD in psychosocial cancer epidemiology in 1994, and his Doctor of Medical Sciences in environmental cancer epidemiology in 2004 from the University of Copenhagen. His main research areas are psychological and social factors in relation to cancer, electromagnetic fields and cancer, and genetic factors in relation to brain tumors.

Preface

It took a long time to get to this idea—that it was reasonable and worthwhile to organize an anthology considering the empirical basis for understanding how personality as a concept and a measurable phenomenon, or maybe only traits of this concept, is associated with various health outcomes. I was driven by my own research results, which frankly speaking were far from what I expected, and by a phone call from San Diego, California, USA. Nikki Levy from Elsevier called me and asked if I was willing to organize and edit an anthology on the concept. I was in a restaurant in Copenhagen with a colleague and at first interpreted the call as a joke. After a while I realized that it was genuine, and I was quite happy that a publishing company so far from Copenhagen had chosen me. This cannot be a hidden truth, I was in fact honored.

Some 25  years ago I was passing by a distinguished colleague in the long corridors of the old Danish Cancer Register, when he asked me if it was not true that I was interested in psychology and cancer. We were standing in an area where, in former times, a circus had its winter quarters; the floor was square, shaped with Italian piazza stones, and the roof was dome shaped, ensuring that the artists could rehearse their breathtaking tricks. I looked at him curiously, because I did not really understand his question; I was almost isolated at the Register, being the only scientist investigating coping, which was at that time a new concept in psychological phenomena, in colorectal cancer patients. The entire institution was occupied at the time with classical cancer epidemiologists researching risk factors for various cancers by either applying the new case–control concept or establishing large cohorts of healthy citizens to investigate diet, physical activity, sexual viruses, and occupational and environmental risk factors. I was somehow on the sidelines, carrying out a cross-sectional study looking at the association between coping and social factors, or at least that was my understanding of the study at that time. I must have had one big question mark on my face because this person, Professor Jørgen H. Olsen, who later became my supervisor and the Director of the Danish Cancer Society Research Center (2011–17), took the pile of papers he had in his hands and put them away on a table. He then took off his coat and his black scarf and, while wiping his glasses, explained to me how a paper that he had just had accepted for publication in the New England Journal of Cancer (Olsen, Boice, Seersholm, Bautz, & Fraumeni, 1995) contained a dataset that I could potentially use for a study in my field of psychology. This dataset was constructed based on information on all childhood cancer patients in the Nordic countries. By linking the personal identification number (PIN; a unique person identifier) of each child to the PIN of his or her parents, it was possible to discover if the parents of childhood cancer patients had an increased risk for cancer themselves, thereby pointing to a potential genetic causation, if such an increased risk was present. The results did not indicate any excess risk among those parents of leukemia, lymphoma, or brain tumor children other than the well-known associations within rare cancer types. The idea that my colleague was discussing came from the ongoing debate about stress. Would it be possible to discover if any of these parents had a higher risk of cancer related to the stress of being a parent to a cancer child, and what about mortality in these parents if the child died? Would we find an excess death rate or would everything be as expected? The research question was interesting and showed that a quite complicated and often discussed topic such as stress could be boiled down to exposure to a major life event. I had never been in this research area before, but suddenly found myself deeply involved in an ongoing controversy between people who defended the position that the mind causes cancer and those who defended the standpoint that it was the methodology by which the research question was investigated that determined the outcome of each study.

I compiled the Danish part of this large dataset and identified more than 11,000 parents who had experienced a child with cancer. At that time, it was considered a privilege to have access to nationwide and population-based incidence rates of cancer and we performed statistical analysis under the assumption that a concept of comparing the observed rates with the expected rates was sufficient to analyze such a large dataset, thinking that all factors of interest had a random distribution. We looked at close to 50  years of cancer incidence and observed that the rates of cancer overall, and when broken down into various cancer sites, did not differ from what we expected based on national cancer statistics and national census data of population numbers in both genders and all age groups. I was surprised, and did not know how to present this finding, as I was convinced that this severe exposure to a parent, including the diagnostic period, treatment periods of up to 2  years of hospitalization involving the child and at least one parent, the difficulties of getting the family and all its members to survive in any aspect of the concept, and the ongoing fear of problems and recurrence if the child survived, would show a clear association with an increased risk for cancer. I did not know how to react properly, in a scientifically sound way, and was further surprised when we discovered that even the death of the child, which happened for thousands of those parents, did not increase the cancer risk. To be more specific, we looked at each cancer type and found no increase in the incidence rates of hormone-associated cancers, like breast and prostate cancer, nor for immune system-associated cancers, like leukemia or cervical cancer, or lifestyle cancers such as lung, bladder, or liver cancer. The study included a mixture of young parents and parents who had had their child diagnosed back in 1943, when the registration of cancer patients began in Denmark, being the oldest cancer registry in the world (Johansen & Olsen, 1997).

I discussed these findings with Professor Olsen and slowly accepted that even my negative study, so to speak, had many positive aspects. Human beings could cope with such enormous challenges without foreseeing an increased risk for cancer. What a wonderful thought to come out with. But what about dying; did the parents die from any other causes more often than their gender- and age-comparable fellow citizens? That question led me into a collaboration with a statistical artist, Mr. Svend Bang, who showed me how it was possible to calculate, for the first time in Denmark, cause-specific death rates. He worked in a small office characterized by piles of papers and documents and satisfied a desire to smoke a cigarette on the premises of the Danish Cancer Society, where it was forbidden to smoke, by holding his arm out of the window. His coffee cup had an imprint of his lips and seemed to be an extension of his somatic self. In addition to these characteristics he was a magician at constructing programs in SAS, which could compute the most difficult of problems. Later, he also developed the so-called primary cancer rates, which have a deep meaning in relation to the science associated with studying the incidence of and risks for cancer.

We found that more than 2000 parents had died, but had absolutely no excess mortality for any type of death or for any cause of death. I was astonished when it was shown that for some lifestyle-associated causes of death, such as cardiovascular diseases, we observed a significantly reduced mortality, pointing to a healthy parent effect, a term we introduced but that was never really accepted in the scientific community. It was a term by which we could show how the communicable effect (not infectious but socially speaking) of a cancer disease in one child could potentially change the entire lifestyle of a family.

I became obsessed, not in a psychiatric way but scientifically, with this question, whether the mind was capable of influencing health, and this was my first major research area—an area for which the conditions in Denmark and other Scandinavian countries are extremely well suited to investigate.

Why is this so? The main characteristic of Scandinavian countries is a relatively homogeneous population of some 23  million people, living in Denmark, Finland, Iceland, Norway, and Sweden. Around the mid-1960s these countries decided to establish a PIN system assigning a 10-digit unique number to all residents to individualize and simplify their taxation and social services data. This number consists of the date of birth and one digit indicating the sex, and is used for all interactions between the individual and the public administration at the national, regional, and municipality levels. In addition, the PIN is used for transactions with banks, employers, and the health system, including general practitioners (GPs), specialized hospitals, and pharmacies, where subsidized and prescribed medications can be bought. For research purposes, access to this wealth of data presents a gold mine of information, which has been used for decades in both clinical and epidemiological research. All studies can be conducted as morbidity studies but not mortality studies; mortality outcomes are an add-on. What does this mean? Well, it is more precise to have information on the diagnosis of a disease by a specialist or a GP than information based on a death certificate as almost no one is autopsied anymore. The disease causing the death, noted on the death certificate, is the best and most qualified guess, but far from the truth. Therefore, morbidity data are one league above mortality statistics when discussing scientific rigor and quality.

Eventually, the mind and cancer story took off. I organized and conducted studies in major life events/stresses, in depression, and in personality as risk factors for cancer. From having a quite simplistic statistical approach we came closer to more fashionable and insightful analytic strategies and discovered in none of these studies an overall risk for cancer. However, we found that persons who experienced a psychological problem, in terms of stress, depression, or a trait in their personality, making it difficult for them to be part of normal social circumstances or enter into and interact in social life seemed to have an increased risk for lifestyle-associated cancers. These persons, we hypothesized, had a lifestyle characterized by a higher consumption of alcohol and tobacco smoking, both well-described and serious risk factors for, e.g., lung cancer or liver cancer. The psychological factor did not cause cancer; it was the lifestyle associated with this factor that had an impact on the risk for these specific cancers. When talking about cause and effect, the mind could not independently cause any cancer; it needed an intermediate—the lifestyle. Therefore, we declared that the mind was not a risk factor for cancer and, in addition, highlighted the methodological aspects of this discussion as the science I organized slowly became more and more sophisticated. Another example is our study on some 1300 survivors from the German concentration camps confirming the link between lifestyle and subsequent cancer disease (Olsen, Nielsen, Dalton, & Johansen, 2015).

The first time I presented these preliminary data was at the International Psycho-Oncology Society Congress in Kobe, Japan, just after the earthquake in 1995, and I remember that I did not understand the full extent of the greater significance of this first dataset in the area of mind and cancer. I stayed at a large hotel and was invited by James Holland, a distinguished professor in oncology from New York (actually James Holland together with colleagues initiated some of the first trials of leukemia chemotherapy treatment in cancer), to share a glass of whisky as he stated that my data were the first solid data presented at this meeting. My insight was further increased when the discussion about the validity and reliability of this first study took off. It suddenly became a discussion not of the findings but of the methodological issues, which seemed much more important. What we showed was that self-reported mind factors (I have been exposed to stress or I have been depressed) were not useful because the recall of diseased individuals was biased by the disease, e.g., a cancer patient tries to explain the cause of his or her cancer by the risk factors typically discussed publicly as causing this particular cancer. Studies relying on the subjects and asking them to recall their exposures showed a positive association with cancer, whereas studies conducted prospectively and using exposure information from a source independent of the subject under study did not confirm the association. As I stated earlier, it suddenly became a discussion of methodology as the reason for the different viewpoints on the association of mind and cancer. In my mind, this is also true for the association of the mind, including personality factors, and other health outcomes such as cardiovascular disease, asthma, allergies, diabetes, or neurological diseases.

This discussion has been carried forward into the entire concept of psychology and survival of cancer or any other chronic or acute disease. There is a culturally based belief that the mind may help us to survive, and thus a healthy mind, positive thinking, and open-minded, cooperative personality fares better than a more closed, introverted personality. Two studies from the mid-1980s appearing in The Lancet and Archives of Internal Medicine, scientific journals that most scientists would love to publish in, showed that cancer patients randomized to either groups headed by a psychiatrist (Spiegel, Bloom, Kraemer, & Gottheil, 1989) or groups undergoing psychoeducation (Fawzy et al., 1990), compared with a control condition, lived longer. The reaction was like a tsunami, as a rush of studies, volunteers, various forms of self-educated therapists, and money went into the psychological oncology research area. I also had my first, aforementioned, grant based on these two studies. This discussion is also relevant in relation to the personality as the exposure under study. How much influence we can assign to the personality becomes the next question, and one could reasonably argue that exposure has no interest if it results in no behavior. Behavior seems to be the acting agent and thereby we can have a discussion of how or if we should divide personality from behavior. I am not quite sure how this dilemma should be solved.

In former times, my position was quite radical, seen from a methodological point of view. I would not be quoted for supporting the idea that the mind causes disease, especially cancer, and I was surprised to learn that a large community of scientists believed and supported the notion that cancer is a psychological disease, assuming that the mind can initiate or promote malformations at a genetic level, causing mutations in the genes of the human cell. I have always had and still have problems with this position, and do not find that the psycho/neuro/immunological literature has shown, convincingly, that psychological or mind exposures can cause somatic changes that have such severity that mutations may occur. On the other hand, the topics chosen for this anthology illustrate that for some of these health outcomes we do have data supporting the idea that the personality may influence the risk for the disease.

In shaping an anthology, an editor should always consider how the various subjects align, and I looked for distinguished scientists who had contributed to this field. It was difficult to recruit volunteers to write chapters for some topics, as these areas have lost credibility as intellectual investments for many academic institutions. They do not add to the H index and thus have no interest. You will find chapters illustrating some basic aspects of the entire field. Chapters of a more general nature, however, touch on personality as a phenomenon, and in another part of the anthology chapters review and discuss the knowledge we have. I was raised as a scientist in the era of environmental cancer epidemiology, which also was the basis for the International Agency for Research in Cancer, the cancer research institution under the World Health Organization. Here criteria were established for causality, and if you apply these criteria to the chapters considering knowledge about personality measures and the risk or prognosis of chronic diseases, you may discuss the strength of the evidence. I have accepted the interpretation of the contributors, but ask readers to make their own observations and reflections.

The anthology has a general section, and also a specific section in this research area. I have chosen some subjects and have left others out. My choice.

I asked a couple of colleagues from the Institute of Psychology at the university to describe the concept of personality as such. I mean, does this phenomenon exist or is it a construct, an abstraction constructed with the purpose of understanding why one human being is different from another? I don’t know, but I think the chapter by Professor Dammeyer and colleagues illustrates this basic aspect and gives some of the background needed for