The Evolution of Suicide

297 Pages·2018·5.424 MB·English

by  C A Soper

Evolutionary Psychology
Series Editors: Todd K. Shackelford · Viviana A. Weekes-Shackelford
C. A. Soper
The
Evolution of
Suicide
Evolutionary Psychology
Series Editors
Todd K. Shackelford
Rochester, MI, USA
Viviana A. Weekes-Shackelford
Rochester, MI, USA
More information about this series at http://www.springer.com/series/10583
C. A. Soper
The Evolution of Suicide
C. A. Soper
Private Practice
Lisbon, Portugal
ISSN 2197-9898 ISSN 2197-9901 (electronic)
Evolutionary Psychology
ISBN 978-3-319-77299-8 ISBN 978-3-319-77300-1 (eBook)
https://doi.org/10.1007/978-3-319-77300-1
Library of Congress Control Number: 2018935263
© Springer International Publishing AG, part of Springer Nature 2018
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To Hattie, Mo, and Fred.
Acknowledgements
This book is based on a PhD thesis that was submitted in August 2017 to the
University of Gloucestershire, England, following research undertaken there from
2014 to 2017.
I would like to record my gratitude to the PhD supervisory team, Emily Ryall,
Jane Monckton-Smith, and Richard Evans; to Adam Hart, Malcolm MacLean, Dave
Webster, and to all at the University of Gloucestershire who enabled this project to
reach fruition. I am grateful for the support of friends and family, particularly to
Sally Birch and David Nicholds, who laboured through earlier drafts and offered
critiques; and to Mark Rousell, who originally pointed me towards evolutionary
psychology.
vii
Glossary of Abbreviations and Neologisms
CMDs Common mental disorders (Goldberg & Goodyer, 2005)
EP Evolutionary psychology (Buss, 2005)
fender Front-line, active, anti-suicide, evolved psychological mechanism
ID Intellectual disability (Lunsky, Raina, & Burge, 2012)
keeper Last-line, reactive, anti-suicide, evolved psychological mechanism
SSSD Self-serving self-deception (Paulhus & Buckels, 2012)
ix
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Definition of Suicide: Deliberate, Intentional Self-killing . . . . . . . . 2
1.2 Suicide as an Evolutionary Puzzle . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.1 Variability, Heritability, and Differential Fitness Effect
of Suicide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.2 Universality of Suicide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.3 Suicide as a Species-Specific Human Behaviour . . . . . . . . . 8
1.3 The Fitness Costs of Death and Suicide . . . . . . . . . . . . . . . . . . . . . 9
1.3.1 The Fitness Cost of Death . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3.2 The Fitness Cost of Suicide . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.3.3 The Fitness Cost of Suicide as a Basis
for a Bargaining Hypothesis . . . . . . . . . . . . . . . . . . . . . . . . 11
1.4 Epidemiology and Theory of Suicide . . . . . . . . . . . . . . . . . . . . . . . 13
1.4.1 Correlates and Unpredictability of Suicide . . . . . . . . . . . . . 14
1.4.2 Recent Developments in Suicide Theory . . . . . . . . . . . . . . . 16
1.5 Aims of the Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.6 The Use of Intuitive Argument and Other
Methodological Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.6.1 Interdisciplinary Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.6.2 Evolutionary Biology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.6.3 Philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.6.4 Evolutionary Psychology . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1.7 S ummary and Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2 R eviewing the Options: Noise, Adaptation, and By-Product . . . . . . . 43
2.1 Suicide as a Result of Genetic Noise . . . . . . . . . . . . . . . . . . . . . . . . 44
2.2 Suicide as an Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.2.1 Reproductive Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
2.2.2 Altruism: Relieving Kin of the Burden
of One’s Existence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
xi
xii Contents
2.3 Suicide as a Maladaptive By-Product . . . . . . . . . . . . . . . . . . . . . . . 57
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3 Suicide as a By-Product of “Pain and Brain”. . . . . . . . . . . . . . . . . . . . 71
3.1 P ain: A Biological Motive for Escape Action . . . . . . . . . . . . . . . . . 72
3.1.1 Pain as Suicide Risk Factor . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.1.2 Evolutionary Adaptiveness of Pain . . . . . . . . . . . . . . . . . . . 73
3.1.3 Suicide as a By-Product of Pain . . . . . . . . . . . . . . . . . . . . . . 77
3.1.4 Inadequacy of Pain Alone as a Condition of Suicide . . . . . . 79
3.2 Brain: Human Cognition Provides the Means to Escape
by Self-Killing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
3.2.1 Epidemiology of Child Suicide . . . . . . . . . . . . . . . . . . . . . . 80
3.2.2 Factors Hypothesised to Protect Children from Suicide . . . 81
3.2.3 Understanding Death, Personal Mortality,
and the Concept of Self-Killing . . . . . . . . . . . . . . . . . . . . . . 83
3.2.4 Organising Suicide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
3.2.5 The Cognitive Floor for Suicide . . . . . . . . . . . . . . . . . . . . . 89
3.2.6 Evolutionary Adaptiveness of Suicidogenic Cognition . . . . 91
3.3 A Theoretical Missing Link: Evolved Defences Against Suicide . . 95
3.3.1 Universality of the “Pain and Brain” Co-authors
of Suicide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
3.3.2 Analogies with Other Costly By-Products of Human
Cognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
3.3.3 Speculations about Timing . . . . . . . . . . . . . . . . . . . . . . . . . . 101
3.4 C onclusion: In Search of Evolved Defences Against Suicide . . . . . 103
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
4 “ Keepers”: Last-Line, Anti-suicide Defences . . . . . . . . . . . . . . . . . . . . 125
4.1 A daptive Defences Versus the “Survival Instinct” . . . . . . . . . . . . . . 126
4.1.1 Keepers: An Evolved Last Line of Anti-suicide
Defences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
4.1.2 The Design of Keepers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
4.2 S uccess Criteria and Manifestations . . . . . . . . . . . . . . . . . . . . . . . . 128
4.2.1 Low but Above-Zero Rate of Suicides . . . . . . . . . . . . . . . . . 128
4.2.2 Residual Suicides Would Be Hard to Predict . . . . . . . . . . . . 129
4.2.3 Keepers Would Associate with Suicidal Thoughts,
Rather than Suicidal Acts . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
4.2.4 Potentially Drastic, but Generally Recoverable,
Non-lethal Outcomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
4.3 Inputs: “Pain and Brain” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
4.3.1 The Emotional Experience of Pain as the Triggering
Input Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
4.3.2 Brain Maturity as a Developmental Condition . . . . . . . . . . 133
4.4 Design Features of Keeper Responses . . . . . . . . . . . . . . . . . . . . . . . 134
4.4.1 “Pain and Brain” Model of Suicide Implies Multiple
Mechanisms by Which Keepers May Forestall Suicide . . . 135
4.4.2 Keeper Responses Will Be Strongly Involuntary
and Subject to “Instinct Blindness” . . . . . . . . . . . . . . . . . . . 135
Contents xiii
4.4.3 Keepers Would Be Functionally Interchangeable:
They May Operate Concurrently or Sequentially . . . . . . . . 136
4.4.4 Protracted Anxiousness as a Common Feature . . . . . . . . . . 137
4.4.5 Keepers May Make the Individual Appear
to Behave Irrationally. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
4.5 Specific Types of Keeper Responses . . . . . . . . . . . . . . . . . . . . . . . . 139
4.5.1 Pain-Type Keepers: Making Suicide Unnecessary . . . . . . . 139
4.5.2 Brain-Type Keepers: Making Suicide Difficult
to Plan and/or Do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
4.5.3 Different Blends of Keepers May Instantiate to Reflect
the Needs of Individual Differences . . . . . . . . . . . . . . . . . . 144
4.6 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
5 C ommon Mental Disorders (CMDs) as Keepers . . . . . . . . . . . . . . . . . 153
5.1 P ain Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
5.2 Brain Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
5.3 Deactivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
5.4 Specific Types of Keeper Responses . . . . . . . . . . . . . . . . . . . . . . . . 160
5.4.1 Pain-Type Keepers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
5.4.2 Potential Multiple Functionalities of Delusions . . . . . . . . . 163
5.4.3 Brain-Type Keepers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
5.5 General Characteristics of Keeper Responses . . . . . . . . . . . . . . . . . 167
5.6 Trade-Off Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
5.7 Manifestations of Successful Operation . . . . . . . . . . . . . . . . . . . . . 173
5.8 Species-Specific and Species-Universal . . . . . . . . . . . . . . . . . . . . . 176
5.9 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
6 “Pain-Type Fenders”: Frontline Anti-suicide Mechanisms . . . . . . . . 195
6.1 General Anticipated Features of Pain-Type Fenders . . . . . . . . . . . . 197
6.1.1 System Inputs and Developmental Onsets . . . . . . . . . . . . . . 197
6.1.2 Obligate, Instinctual Responses . . . . . . . . . . . . . . . . . . . . . . 198
6.1.3 Deactivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
6.2 Regulating the Experiencing of Painful Events by Self- Serving
Self- Deception (SSSD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
6.2.1 The Previewing and Editing of Bad News . . . . . . . . . . . . . . 199
6.2.2 Psychodynamic Defences and Self-Serving
Self- Deception (SSSD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
6.2.3 The Evolution of SSSD . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
6.3 The Delusional Basis of Subjective Well-Being (SWB) . . . . . . . . . 207
6.3.1 Fenders and the Evolution of Systematic Irrationality . . . . 208
6.3.2 Fender Defences and the Fitness Value of Organised
Misbelief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
6.4 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222