Download An intrapersonal conflict perspective

Customization of psychosocial stress
effects on human health: an
intrapersonal conflict perspective
Patrick Sandoz
Institut FEMTO-ST, Université de Franche-Comté, UMR CNRS 6174,
Besançon, France
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ABSTRACT
From etiologic, clinical or public health perspectives, differences in psychosocial
stress responses remain a huge scientific and medical challenge. We address
the customization of psychosocial stress responses in humans by considering
our dual character of independent organisms and interdependent social group
members as a source of intrapersonal conflicts. By challenging our subjective
representations on our social identity, psychosocial stress triggers or exhibits
intrapersonal conflicts and may enhance divergence between physiologicallydriven and psychosociologically-driven internal forces. In this perspective, our
individual-specific brain development constitutes a major cause of interindividual
variability since it impacts the overall stress-to-disease links.
We propose a two-step stress-to-disease etiological chain: i) stress perception
and appraisal and ii) response to actually perceived stress. We argue that the first
step of stress perception and appraisal is more affected by interindividual variability than the second step of response to actually perceived stress. A psychocognitive approach correlating symptoms with actually perceived stress is proposed to address the epidemiology of psychosocial stress effects. The ability of
this approach to reduce interindividual variability biases is discussed.
From this perspective, pathological effects of psychosocial stress might be questioned as possible conflict responses internally emerging as the lesser evil, thus
corresponding to adaptation attempts.
Keywords: Stress response customization, Intrapersonal conflicts, Solitary versus social duality, Stress-related diseases, Interindividual variability, psycho-cognitive epidemiology
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INTRODUCTION
Psychosocial stress is acknowledged as a major cause of mental and physical diseases and its role
is still reinforced by recent evolution in western lifestyles (Holmes and Rahe, 1967; Thoits, 2010;
Dallman, 2010). Stress research remains however very recent in regard to over-two-thousand
years of medicine history. Walter Cannon first linked the adrenal activity with major emotions
and pain and discussed their role in animal life (Cannon, 1914). The contribution of Hans Selye’s
to the elucidation of the role of the HPA axis in the stress response has also to be noticed. He
introduced the concept of ‘diseases of adaptation’ to signify that if it is maintained for too
long, the stress response may become detrimental to the organism (Selye, 1946). Since these
early times, progresses in knowledge and instrumentation allowed significant advances in the
understanding of stress mechanisms. The concepts of ‘allostasis’, ‘allostatic load’ and ‘stress
response system’ were introduced and explored at both physiological and behavioral levels
(McEwen and Stellar, 1993; Korte et al., 2005; Ellis et al., 2006). An ever-increasing number of
molecules have been identified to play an active role in the neuro-symphony of stress (Joëls and
Baram, 2009). Stress is also known to affect several generations of individuals through epigenetic
mechanisms of which contribution to adaptation and evolution comes into question (Richards,
2006; Jablonka and Raz, 2009).
The causes of individual differences in stress responses remain a major challenge in the field
despite the contributions of both genetic and environmental factors across the lifespan have been
considered (McEwen and Stellar, 1993; Ellis et al., 2006; Semmer, 2003; Dolinoy et al., 2007).
Most attention was however paid to the worthwhile elucidation of the elementary physiological
processes triggered by stress exposure. Corticosteroid hormones were thus the subject of in-depth
studies and are now considered as biomarkers of the stress level (Romero, 2004). Much less
attention was paid to the mechanisms of stress perception and appraisal involving not only the
autonomic nervous system (ANS) of individuals but their overall cognitive abilities (McEwen
and Sapolsky, 1995; Henderson et al., 2012). We consider this state of fact as a major cause of
our poor understanding of differences in stress responses (Engel, 1977).
This paper addresses differences in psychosocial stress responses from a systemic perspective
based on intrapersonal conflicts. As member of a social species, each human being has a dual
status of independent organism and of interdependent social group member. This duality is
intrinsic to the human condition and constitutes a source of intrapersonal conflicts. As an external
force applied to the individual functioning, psychosocial stress can act as a trigger or exhibitor of
intrapersonal conflicts and its effects on human health are considered in this perspective. Stressinduced intrapersonal conflicts are highly-customized because of the influence of unshared
environment and life experiences on brain development.
We propose to model the action of stress on human health by a two-step process; i) stress
perception and appraisal and ii) response to actually perceived stress. We then argue that
the relative degrees of interindividual variability of these two steps are different and propose
a psycho-cognitive epidemiological approach that would correlate symptoms with actually
perceived stress rather than with external stress exposure. Finally, the adaptive value of stress
responses is questioned in light of the proposed intrapersonal conflict perspective.
INTRAPERSONAL CONFLICTS AS NATURAL HUMAN ATTRIBUTES
Internal conflicts appear naturally in complex structures made of sub-elements that become
interdependent on each other despite potentially divergent interests. Such internal conflicts
were successfully explored in different species and configurations (Trivers, 1974; Haig, 2006a;
Del Giudice, 2012). The human species is exposed to such internal conflicts that exist at
various levels, from the intragenomic level to the inter-community level. Those opposing
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Figure 1. Different levels of human organization. Human beings exist simultaneously in both
physiological and psychosocial spaces.
the organismic and social levels of organization are however of specific importance because
of the social organization of the human species. As a complex result of evolution humans
belong to a social species that evolved from solitary animal ancestors. The solitary and social
characters are antagonist: we have independent bodies but we are interdependent people. We
are concerned by our fellows and interdependent on them (solitary animals are not) but we
keep individual autonomy. Furthermore no definitive hierarchy does exist between individual
and social organization levels and the actual priority may depend on both circumstances and
concerned individuals. We are thus members of a social species with an intermediate degree of
cooperation-dependence between one another.
With regard to life evolution, the social level of human organization is the most recent and
has not been optimized by natural selection yet. Its functioning remains conflicting and rapidly
transforming across generations as confirmed by human history. We may even consider that
an additional stage of social transformation is being experienced currently as induced by the
new technological tools for electronic communication now available (Rifkin, 2000). At present
time, no complete evolutionary-selected coordination process of the organismic and social levels
of human organization does exist. This state of fact makes the coordination of the organismic
and social levels particularly problematic. By exerting an external force on individual functioning, psychosocial stress may disturb the organismic versus social balance at the level of each
individual and thus contribute to the ongoing process of social transformation. As expressed by
Sapolsky, because of recent changes in western lifestyle: Our current patterns of disease would
be unrecognizable to our great-grandparents or, for that matter, to most mammals (Sapolsky,
2004).
As depicted in Fig.1, human functioning involves a cascade of three main organization
levels: cellular, organismic and social. The figure emphasizes on the fact that human beings exist
simultaneously within two distinct spaces; respectively physiological and psycho-sociological,
whereas the cellular and social organization levels exist in a single space. This specificity of the
organismic organization level is a source of intrapersonal conflicts opposing different dimensions
of ourselves; i.e. solitary organisms versus interdependent social group members. The resulting
solitary versus social duality was inherited from life evolution and exists in diverse social species.
It is however paramount in the human species since we present the most sophisticated pattern of
interindividual interaction. A formal acknowledgment of the existence of this solitary versus
social duality can be found in the diverse meanings attributed to the word self : the immune self
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representative of our body and the psycho-cognitive self (PCS) representative for our embedded
social identity. Some analogy with Dawkins’ distinction between the concepts of genes and
memes could also be drawn (Dawkins, 2006).
From an evolutionary biology perspective, both solitary and social human characters can
be related to an optimal rate of gene replication but to different extents however. In the solitary
case, gene replication is only considered through individual’s survival and reproductive success
as in the case of solitary animals. In the social case, the possibility of gene replication via
the reproductive success of relatives is considered, the importance of individual’s survival and
reproduction is thus decreased (Queller and Strassmann, 1998; Clutton-Brock, 1988). We
have however to bear in mind that evolutionary biology applies to long-term statistics based
on populations and that unadaptive options occur at the level of a single individual’s life.
Furthermore, as described by Haig, adaptive solutions may lack in response to new kinds of
environmental challenges (Haig, 2006b).
As the main regulation center of human beings, the human brain is the privileged locus of
this solitary versus social duality. Our brain cumulates indeed two simultaneous but clearly
different functions: i) As in our solitary animal ancestors, our brain is the systemic coordinator
of cell activity ensuring the harmonious functioning of the whole organism. At this physiological
level, individuals are expected to function to the best of their own interests as independent beings;
i.e. driven primarily by survival and reproduction forces. ii) As members of a social species, our
brain is also involved in the coordination of social interactions. At this psycho-sociological level,
individuals are expected to function to the best of their own interests as social group members;
i.e. favoring primarily subjective social-identity forces. At every moment of one’s life, his brain
has to trigger the optimal regulation mechanisms to fulfill at best his dual function. This double
responsibility of the human brain is the functional correlate of the solitary versus social duality
discussed above. The interdependence of the different brain areas, especially the ANS and
the CNS, is consistent with this brain function to match physiological and psycho-sociological
processes with one another (Damasio, 2012). This dual function of the human brain is also
consistent with the ”Social Brain Hypothesis” that attributes the large brain volume of primates,
especially that of the neocortex, to the wide social abilities that it provides (Dunbar, 1998;
Adolphs, 2009).
One comment is necessary at this point: the word “brain” is used here with a generic
meaning. This denomination hides the huge complexity of neurological processes, including for
instance the fine interactions between the endocrine, immune and central nervous systems or
gut-brain communications (Damasio, 2012; Edelman, 1992; Ader et al., 1995; Mayer, 2011).
DIFFERENCES IN PSYCHOSOCIAL STRESS RESPONSES
Psychosocial stress is unable to harm our body directly and its effects on human health are necessarily indirect; resulting from some kind of body response to the external adversity experienced.
The effects of psychosocial stress on human health have thus to be considered as a two-step
process as depicted in Fig. 2.
In regard to intrapersonal conflicts discussed previously, we may say that psychosocial stress
challenges human beings only at the level of their subjective social identity. The first phase of
stress action corresponds thus to stress perception and appraisal by the individual and produces
the actually perceived stress. The latter can be described as the internal strain due to mismatch
between the external context appraisal and the subjective expectations peculiar to the individual’s
PCS. This stress perception and appraisal phase is acknowledged by Sapolsky’s words: It’s not
just the external reality; it’s the meaning you attach to it (Sapolsky, 2004). If the perceived
stress is intense enough, some subconscious internal adjustments may occur and thus trigger the
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Figure 2. Two-step model of psychosocial stress action on human health.
second phase of response to the stress perceived. The actual effects of psychosocial stress on
human health result thus from this second step of response to the internally perceived stress.
If a second step of response to the perceived stress is actually triggered, two cases can be
distinguished: i) If internal adjustments affect the individual only at the level of its social functioning, stress effects will concern its psychological and mental health with minor physiological
changes only. ii) If internal adjustments affect the individual at the wider level of its organismic
versus social balance, stress effects will step across the psycho-sociological / physiological
barrier and physiological outcomes will also appear. In this case, the constraint applied to the
social regulation function of the brain is so important that the physiological regulation function
of the brain is also disturbed.
Differences in psychosocial stress responses can be addressed from the relative interindividual
variability of these two steps of stress action on human health.
At the stress perception and appraisal stage, external stress exposure is appraised relatively to
subjective representations peculiar to the individual’s PCS. Let’s discuss the degree of interindividual variability tied to the progressive elaboration of the individual’s PCS during childhood.
In accordance with Mahler’s description of the psychological birth of the human child, the
newborn’s separation-individuation process is progressive, spreads over several years, and starts
only 4 or 5 months after birth for its first sub-phase (Mahler et al., 1975). The child’s relationship
with his surroundings, especially with his mother as the main attachment figure, provides his
first social experiences from which he builds his own representations of what he can expect from
others and how to best answer their expectations (Swain et al., 2007). Brain development thus
allows the construction of the child’s PCS as well as the acquisition of customized knowledge
about the world through interactions with his caregivers (Fonagy et al., 2007). M. Small even
asserts : Societies raise their children so that they grow into adults who behave in a way valued
by that society (Small, 1998)1 . The customized sociocultural knowledge thus accumulated
1 cited
by Sapolsky (2004)
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during childhood is structurally ”written” in the synaptic networks which establish and reinforce
continuously following selective processes (Edelman, 1992; Pascual-Leone et al., 2005; Toga
et al., 2006). As such a result of a long elaboration process intertwining genetic data with
unshared socio-environmental experiences, the individual’s PCS presents a maximal degree of
interindividual variability.
We argue that the second phase of response to the perceived stress presents a lower degree of
interindividual variability because of several reasons: i) Internally perceived stress states can be
related to some kind of negative emotions of which number is not infinite (Ekman, 1992; Barrett,
2012). ii) The number of actual psychosocial stress effects on human health; either physiological
or psychological, is also limited. iii) Causality links associating specific perceived stresses with
particular body responses were sorted out by natural selection across evolution, thus decreasing
the remaining number of active cause-to-effect paths.
We thus defend the hypothesis that even if both steps of stress effects on human health
contribute to differences in stress responses, the first phase of stress perception and appraisal
is subject to a higher degree of interindividual variability than the second phase of response to
actually perceived stress.
EPIDEMIOLOGICAL PROSPECTS
Toward psycho-cognitive epidemiology?
The distinction of two successive steps in the action of psychosocial stress on human health as
well as the hypothesis of a lower interindividual variability for the second phase of response to
actually perceived stress offer new epidemiological prospects. With the aim to obtain increased
correlation levels, the idea consists in addressing a single step of the stress action process at once;
the most interesting one corresponding to the second phase of response to actually perceived
stress.
New psycho-cognitive epidemiology protocols can thus be thought of to explore possible
causality between perceived stresses and particular diseases. In this aim, the new tools for
brain activity observation now available could be used to compare the brain activation of people
suffering from one disease with respect to a control population in response to a set of stressful
stimuli. This set of stimuli would be elaborated to trigger specific internal states (or feelings,
or emotions such as fear, danger, disgust, disappointment, loss, abandonment, exclusion, etc.).
The purpose of such studies is to look for actual correlations between a disease and particular
internal states that would be more easily excited and with higher magnitude in affected patients
than in the control group. Less expensive instruments able to quantify internal stress markers, for
instance heart rate variability (Thayer et al., 2012), could also be used in such psycho-cognitive
epidemiology studies.
A supplementary interest of the proposed psycho-cognitive epidemiological approach is
to minimize the voluntary human implication in protocols and thus to avoid some subjectivity
biases. We finally note that even if our hypothesis of a lower variability for the second phase of
response to perceived stress is false, the fact to consider a single step of the stress action process
instead of both is already sufficient to reduce the variability rate and thus to expect improvements
in the eventual rates of correlation.
Adaptive value of psychosocial stress responses?
At every life instant our brain has to select and trigger the most appropriate set of regulation
commands. In the face of stressful conditions, this function may become problematic and human
dysfunctions can be questioned from such an adaptation perspective (Jablonka and Raz, 2009;
Haig, 2006b; Nesse, 2000). The acknowledgment of the existence of solitary versus social
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intrapersonal conflicts intrinsic to the human condition sheds a new light on these questions.
Individual’s health is not the only purpose of the human brain but is put in balance with
conflicting, subconscious and customized social expectations. Trade-offs partly detrimental to
the body can thus be expected, especially in response to psychosocial stress that challenges our
subjective social representations. A harmful stress response can thus be questioned as the most
appropriate option internally selected by the individual’s brain; i.e. subconsciously appraised as
the lesser-evil conflict-outcome. Such a surprising possibility has however to be considered in
regard to the following evolutionary pitfalls:
i) Recent transformations in western lifestyle induce new situations for which no adaptive
solution was acquired by our ancestors. As D. Haig says: Without doubt, our current environment
presents us with novel challenges for which we lack specific adaptations... Retirement planning
is a recent innovation for which we are unlikely to have evolved dedicated mechanisms. Instead,
we employ general-purpose problem-solving machinery to make plans that come into conflict
with more hard-wired responses (Haig, 2006b).
ii) The human brain is a complex structure combining different sub-elements that appeared
progressively and successively across life evolution. This slow increase in complexity allowed
improvements in the perception of the outside world with ever more details and differences. This
refinement capability is paramount in humans, especially because of language that allows us
almost infinite degrees of differentiation and abstraction. The effects of psychosocial stress on
human health involve these refinement capabilities in the reverse direction; from the neocortex
to more ancient brain areas; i.e. from the finer to the coarser. The associated semiotic regression
is a possible source of mis-adjustment as already pointed out eighty years ago by Korzybski
(Korzybski, 1933). Recently, Eisenberger and Cole reviewed the neurological mechanisms
linking social ties with physical health. They suggest that: threats to social connection may tap
into the same neural and physiological ‘alarm system’ that responds to other critical survival
threats, such as the threat or experience of physical harm. Similarly, experiences of social
connection may tap into basic reward-related mechanisms that have inhibitory relationships
with threat-related responding (Eisenberger and Cole, 2012).
These observations suggest that beside stress physiology, some kind of stress cognition is
desirable to elucidate how meaning propagates across the different brain areas. This further step
appears necessary to progress in our understanding of human responses to psychosocial stress
in regard to evolutionary-inherited adaptation processes and despite the huge difficulty raised
by the customization of stress perception and appraisal. This cognitive challenge is included in
the more general issue of the role of information in adaptation and evolution (Danchin, 2013;
Laland et al., 2014).
SUMMARY
We discussed differences in psychosocial stress effects on human health from a systemic perspective based on intrapersonal conflicts. Such intrapersonal conflicts were already reported in
humans and Haig pointed out clearly that humans are at once rational, cultural and instinctive
beings (Haig, 2006b; Campbell, 1975). The strength of the proposed approach lays on the
distinction between the solitary and social characters of human beings. From an evolutionary
perspective, this distinction corresponds to the transition from solitary animals; interacting with
their environment only, to social species; of which members interact with both environment and
fellows. We also consider the social function of the human brain and observe that individual
versus group conflicts trigger intrapersonal conflicts. The latter are highly customized because
of postnatal brain development.
The action of psychosocial stress on human health is represented by a two-step process: i)
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stress perception and appraisal and ii) physiological response to actually perceived stress. We
defend the hypothesis that the first step is more affected by interindividual variability especially
because of unshared experiences during childhood. This hypothesis is in accordance with
growing evidence for developmental origins of human health and disease (Dolinoy et al., 2007;
Gillman, 2005).
We finally outline the possibility for psycho-cognitive epidemiological studies correlating
symptoms with actually perceived stress. The cognition challenge raised by the propagation of
meaning across the different brain areas is also pointed out.
Conflict of interest
The author declares no conflict of interest.
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