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UC Davis Previously Published Works
Title
Beyond risk, resilience, and dysregulation: phenotypic plasticity and human
development.
Permalink
https://escholarship.org/uc/item/860218g3
Journal
Development and psychopathology, 25(4 Pt 2)
ISSN
0954-5794
Authors
Belsky, Jay
Pluess, Michael
Publication Date
2013-11-01
DOI
10.1017/s095457941300059x
Peer reviewed
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University of California
Beyond risk, resilience, and dysregulation: Phenotypic plasticity
and human development
JAY BELSKY
a,b,c
AND MICHAEL PLUESS
d
a
University of California, Davis;
b
King Abdulaziz University;
c
Birkbeck University of London; and
d
Queen Mary University of London
Abstract
We provide a theoretical and empirical basis for the claim that individual differences exist in developmental plasticity and that phenotypic plasticity should
be a subject of study in its own right. To advance this argument, we begin by highlighting challenges that evolutionary thinking poses for a science of
development and psychopathology, including for the diathesis–stress framework that has (fruitfully) guided so much empirical inquiry on developmental risk,
resilience, and dysregulation. With this foundation laid, we raise a series of issues that the differential-susceptibility hypothesis calls attention to, while
highlighting findings that have emerged over just the past several years and are pertinent to some of the questions posed. Even though it is clear that this new
perspective on Person Environment interaction is stimulating research and influencing how hypotheses are framed and data interpreted, a great many
topics remain that need empirical attention. Our intention is to encourage students of development and psychopathology to treat phenotypic plasticity as an
individual-difference construct while exploring unknowns in the differential-susceptibility equation.
Empirical research on risk and resilience first emerged in the
1970s (e.g., Garmezy, 1974; Rutter, 1979; Werner & Smith,
1977) and has come to exert a major influence on the study of
development and psychopathology (for reviews, see Lutha r,
Cicchetti, & Becker, 2000; Masten, 2007; Rutter, 2012).
One of the most important and valuable insights that emerged
over the past decades has been that individuals differ in the
degree to which they are affected by contextual adversity.
Whereas some “vulnerable” children and adults are likely
to develop problematically in response to negative contextual
conditions by becoming emotionally and/or behaviorally dys-
regulated, others are not and are thus regarded as “resilient.”
Empirically observed variability in vulnerability to con-
textual adversity accords nicely with the widely embraced,
if not always labeled, diathesis–stress framework (Gottesman
& Shields, 1967; Monroe & Simons, 1991; Zuckerman,
1999). This perspective stipulates that some individuals are
disproportionately, if not exclusively, likely to succumb to
the negative effects of some contextual stressors (e.g., child-
hood maltreatment, insensitive parenting, poverty) and be-
come psychologically and/or behaviorally disturbed and dys-
regulated, if not disordered. This heightened vulnerability to
adversity may be due to organismic characteristics of the in-
dividual, such as genetic makeup, personality, or tempera-
ment, or even family factors and processes or extrafamilial
conditions. Perhaps nowhere else has diathesis–stress think-
ing explicitly or implicitly guided recent empirical inquiry
more than in the study of Gene Environment (G E) inter-
action (e.g., Caspi et al., 2002).
One of the challenging issues that arises with respect to di-
athesis–stress motivated G E research has to do with under-
standing why natural selection would craft an organism to re-
spond to adversity by becoming disordered or dysregulated.
That is, what could be the pay-off of developmental dysfunc-
tion? As we clarify in the next section, the answer to this
question emerges upon challenging another prevailing notion
that is commonly encountered in the literature on develop-
ment and psychopathology, that of “optimal development.”
Thus, the first major section of this paper raises some evolu-
tionary-inspired challenges to diathesis–stress thinking and,
more generally, the science of development and psychopa-
thology. Although evolutionary theory has made inroads re-
cently into these arenas of inquiry (see the 2011 Special Sec-
tion of Development and Psychopathology edited by Ellis and
Boyce and 2012 Developmental Psychology edited by Ellis
and Bjorklund), it would still be fair to say that developmen-
tally oriented scholars have been among the slowest to em-
brace an evolutionary perspective. We seek to change that
and join the limited company of others, some of whom
have encouraged such an orientation relatively unsuccessfully
for quite some time (Belsky, Steinberg, & Draper, 1991;
Bjorklund & Pellegrini, 2002; Daly & Wilson, 1980, 1981).
The evolutionary-inspired challenges to prevailing think-
ing about development and psychopathology that we high-
light in the next section, including the diathesis–stress frame-
work, lead to the conclusion that developmental plasticity
should be regarded as a phenotype in its own right, that is,
as an individual-difference construct, something students of
animal behavior are becoming ever more appreciative of
Address correspondence and reprint requests to: Jay Belsky, Human and
Community Development, University of California, Davis, One Shields Ave-
nue, Hart Hall, Davis, CA 95616; E-mail: jbelsky@ucdavis.edu.
Development and Psychopathology 25 (2013), 1243–1261
#
Cambridge University Press 2013
doi:10.1017/S095457941300059X
1243
(Dingemanse, Kazem, Reale, & Wright, 2010; Mathot et al.,
2011). This claim calls attention to a new and evolutionary-
inspired way of thinking about PersonEnvironment interac-
tion: the differential-susceptibility framework (Belsky, 1997,
2005; Belsky, Bakermans-Kranenburg, & van IJzendoorn,
2007; Belsky et al., 2009; Belsky & Pluess, 2009a; Boyce
& Ellis, 2005; Ellis, Boyce, Belsky, Bakermans-Kranenburg,
& van IJzendoorn, 2011). In an attempt to further inquiry in
this area, we highlight future directions for research and the-
ory by highlighting some new empirical findings in the sec-
ond major section of this paper. Then, we draw some general
conclusions in the final section.
Evolutionary Challenges to a Science of Development
and Psychopathology
Optimal versus adaptive development
Much theory, research, and writing about development and
psychopathology today is based on what has been described
recently as the “mental health model” (Belsky, 2008) or “de-
velopmental psychopathology model” (Ellis et al., 2012;
Frankenhuis & Del Giudice, 2012). Central to this theoretical
and empirical framework is the implicit if not explicit as-
sumption that there is something ubiquitously referred to in
the developmental literature as “optimal” development. The
notion of optimal development more or less implies that it
is the natural condition of humans from youth to later in
life to become secure, autonomous, self-controlling, proso-
cial, achievement striving, intimate in the context of pair
bonds, hardworking, sensitively responsive in parenting,
and generative in the next generation, as well as physically
healthy, happy, and long lived. Development goes awry
(i.e., becomes dysregulated) when forces direct it from its nat-
ural or otherwise anticipated course. Thus, being insecure, de-
pendent, impulsive, antisocial, a risk taker, an insensitive par-
ent, and/or depressed are implicitly if not explicitly regarded
as developmental outcomes that nature did not intend.
However, an evolutionary perspective challenges this pre-
vailing view of so-called dysfunctional, dysregulated, or mal-
adaptive development, especially when, consistent with di-
athesis–stress thinking, it arises within settings of adversity
(Belsky, 2008; Daly & Wilson, 2005; Ellis, 2004; Ellis,
Boyce, et al., 2011; Ellis et al., 2012; Hinde & Stevenson-
Hinde, 1990). Because stressful and supportive environments
have been part of human experience throughout our evolu-
tionary history, evolutionists conceptualize developmental
systems as shaped by natural selection to respond adaptively
to both kinds of contexts. From this perspective, the experi-
ence of encountering stressful environments does not so
much disturb, or dysregulate, development as direct, or regu-
late, it toward strategies that are or at least once were bio-
logically adaptive under conditions of adversity. Moreover,
by adaptive we mean functional and perhaps even optimal,
given the circumstances in which the individual finds him/
herself, in that they directly or indirectly promoted the indi-
vidual’s reproductive fitness. (See below for further discus-
sion of this fundamental goal of all living things.)
Some of the most compelling evidence highlighting the
validity of the adaptational perspective just outlined can be
found in the much-heralded rodent work showing that what
is regarded by many as “low-quality” maternal care in the
rat, as reflected in limited licking and grooming of the new-
born pup, modifies stress physiology and brain morphology,
but in functional and strategic rather than maladaptive
ways. Even though evidence of higher corticosterone levels,
shorter dendritic branch lengths, and lower spine density in
hippocampal neurons would appear to provide indisputable
evidence of negative effects of early experience, such
presumptively nonoptimal developments appear strikingly
functional, given the conditions that gave rise to them. This
is because the developmental experiences in question en-
hance learning and memory processes under stressful con-
ditions (Champagne et al., 2008). Moreover, such putatively
disturbed or dysregulated physiological and morphological
changes promote central features of defensive and reproduc-
tive strategies (behavior under threat, open-field exploration,
pubertal development, sexual behavior, and parenting;
Cameron et al., 2005) in ways consistent with evolutionary
models of adaptive reproductive strategies (Belsky et al.,
1991; Chisholm, 1993), a subject we consider in greater detail
below.
Ultimately, developmental adaptations to high-stress envi-
ronments enable individuals to make the best of a bad situa-
tion (i.e., mitigate inevitable fitness costs), even though “the
best” may still constitute a high-risk strategy that jeopardizes
the person’s health and s urvival (e.g., Mulvihill, 2005;
Shonkoff, Boyce, & McEwen, 2009). It is certainly possible
to view many of the developmental sequelae of child mal-
treatment in this manner. After all, it is not difficult to appreci-
ate the developmental “wisdom” in being especially vigilant
to threat, engaging in biased attributions or behaving aggres-
sively if the lessons of a painful life have taught one to “act
first and ask questions later” and “presume the worst rather
than the best of people.” By the same token, the indiscrimi-
nant friendliness of institutionally reared children (Baker-
mans-Kranenburg et al., 2011) could be regarded as a highly
functional strategy for seeking help and support in a world
that has offered little, even if it looks disturbed or disordered
from the perspective of family-reared children.
Reflection on th ese observations should clarify why nat-
ural selection may have crafted human development to re-
spond to certain conditions by making individuals behave
in ways we now regard as disturbed, dysfunctional, dysregu-
lated, psychopathological, and nonoptimal. As such, this
analysis perhaps strengthens the theoretical foundations of di-
athesis–stress thinking that we questioned earlier. That is, one
can now understand why nature may have crafted at least
some individuals to respond to adversity by developing in pu-
tatively disturbed and dysregulated ways. Nevertheless, it re-
mains our view that the potential costs of not responding to
adversity in a putatively dysfunctional, dysregulated, and dis-
J. Belsky and M. Pluess1244
ordered manner merits more consideration by students of de-
velopment and psychopathology than it has been given. Thus,
in addition to considering the possible benefits of behavior re-
garded by many as dysregulated and problematic, students of
development and psychopathology would be well advised to
consider what the costs may be of behaving, given the cir-
cumstances some live in, in those ways that mainstream think-
ing labels as optimal.
The argument advanced here ultimately calls into question
the use of the term optimal when discussing development and
suggests that there could be substantial merit in thinking more
in terms of why it may actually make good sense for children,
adolescents, and adults to behave in the dysregulated and
troubled ways in which they do. However, such a perspective
does not mean abandoning efforts to reduce psychological
pain and suffering. What it suggests is that to do so most ef-
fectively may require consideration of the payoffs and trade-
offs that may have resulted in natural selection crafting an or-
ganism to develop and behave in the way we observe them to,
especially under conditions of adversity. We suspect that in-
tervention efficacy could be enhanced if interventionists seri-
ously considered “biological gravity” (natural selection has
crafted phenotypes that serve to enhance fitness) when de-
signing programs rather than think only in traditional mental
health terms about what behavior is optimal and what is not.
Much like the efforts of would-be aviators who predated the
modern ones who eventually came to grips with physical
gravity, thereby recognizing the need for lift and propulsion
before they could fly, some intervention efforts reflect little
more than attaching wings to the arms and jumping off cliffs.
Without understanding the nature, origin, and function of dis-
ordered and dysregulated behavior, including its evolutionary
basis (i.e., biological gravity), the likelihood of preventing or
remediating it may be seriously compromised. Ellis and as-
sociates (2012) develop this point further in the case of ado-
lescent risk taking, highlighting existing interventions that
appear consistent or inconsistent with evolutionary thinking
as well as offering novel, evolutionary-inspired ones.
Probabilism versus determinism
It is widely appreciated by developmentalists today that fac-
tors that shape human development typically do so in a prob-
abilistic rather than deterministic fashion. That is, forces that
we expect to enhance or undermine human functioning, in the
traditional mental health sense, will not always do so, even if
they sometimes, or even often, do so. This probabilistic nature
of development also needs to be appreciated in its evolution-
ary basis, something that seems forgotten when it is argued
that disturbances in development could not reflect evolution-
ary adaptations because they so often lead to failure, includ-
ing perhaps failure to disburse genes in future generations
in the modern western world. Two points merit consideration
in response to this seemingly reasonable observation.
The first is that natural selection is backward not forward
looking, selecting phenotypes that have fostered fitness in
the past. This means that what was once evolutionarily adap-
tive may no longer be so today. However, even if that is true,
which should not necessarily be the default assumption, it
would not “biologically” follow that the neurobiological
and psychological processes that gave rise to them in the first
place would have been short circuited in order to no longer
engender the behavioral functioning that is typically regarded
as problematic today. If that were the case, it would be easy
to override the human proclivity to consume sugary foods.
After all, this penchant for sweets evolved at a time when
such substances were rarely or intermittently available, yet
in the modern world today they are continuously available
and abundant. Thus, even if a developmental process no
longer achieves the goal it was selected to realize but instead
engenders developmental problems in the modern world
(e.g., obesity), the process itself likely remains operative be-
cause of the time it takes for evolution to engineer genetic
change.
The second point regarding probabilism and nonoptimal
development is that, for selection to take place, a phenotype
does not have to always or often succeed in enhancing fitness;
it only needs to have done so more often than alternative phe-
notypes once did (Frankenhuis & Del Giudice, 2012). More-
over, the costs of failure need to be weighed against the ben-
efits of success (Ellis et al., 2012; Figueredo & Jacobs, 2010;
Frankenhuis & Del Giudice, 2012). Thus, even if antisocial
behavior or depression or teenage pregnancy seem counter-
productive from either a mental health or fitness standpoint
and could have proven so in the past (failing more often
than succeeding), such putative disturbances in development
could still have been selected, especially when a low-fre-
quency success engendered a substantial payoff. What this
implies, of course, is that some putatively dysregulated be-
havior will be of the high-stakes’ variety: unlikely to succeed
yet succeeding hugely when it does.
What is development trying to achieve?
The concept of optimal development is most certainly in-
tended to capture phenomena like health, happiness, security,
longevity, and other indisputably highly valued life condi-
tions. On the basis of much developmental writing, it would
not seem misguided to infer that nature has crafted human de-
velopment to achieve such outcomes. From an evolutionary
perspective, however, this is certainly not (exclusively) the
case. Although security, good health, happiness, and a long
life may be the means by which some or many individuals
successfully pass genes on to future generations and promote
their more general inclusive fitness, especially when growing
up and living under benign or benevolent conditions, there is
no reason to presume that these phenotypes achieved or can
achieve these same ends under all conditions, especially con-
trasting conditions. This observation was central to Belsky’s
(in press; Belsky et al., 1991) effort to recast socialization the-
ory in evolutionary perspective two decades ago, which was
built on Draper and Harpending’s (1982) evolutionary insight
Phenotypic plasticity 1245
about why father absence may be related to “promiscuous”
sexual behavior on the part of females.
Rather than presuming that development was crafted by
natural selection to yield phenotypes reflective of optimal de-
velopment, Belsky et al.’s (1991) psychosocial acceleration
theory and its derivatives (Chisholm, 1993; Del Giudice,
2009; Del Giudice, Angeleri, & Manera, 2009; Ellis, 2004;
Ellis & Garber, 2000; Frankenhuis & Panchanathan, 2011;
James, Ellis, Schlomer, & Garber, 2012) are founded on the
premise that the ultimate goal of all living things, including hu-
mans, is to disperse their genes to future generations and that
the means of achieving this fitness end is contextually contin-
gent. Thus, what works under certain developmental condi-
tions does not necessarily work under others. It is ultimately
for this reason that the notion of optimal development is funda-
mentally problematic: what is optimal in one (modern and well
resourced?) context may not be so in another.
We submit that students of development and psychopa-
thology would do well to think in fitness terms when trying
to understand phenotypes of concern. Upon doing so, what
is regarded as dysregulated, dysfunctional, disturbed, or dis-
ordered may come to be seen in a new and informative light,
a point recently made by Ellis and associates (2012) with re-
spect to adolescent risk taking. Once again, however, an evo-
lutionary perspective with its emphasis on selection of pheno-
types that foster the dispersion of genes in future generations
does not mean that nothing should be done. Such would re-
flect succumbing to the naturalistic fallacy, inferring what
“ought to be” from what “is,” a long-derided perspective.
However, we do suggest that seeing development the way nat-
ural selection views it may facilitate efforts to address con-
temporary concerns.
Fast versus slow development
Because of its grounding in evolutionary life-history theory
(Kaplan & Gangestad, 2005 ; Stearns, 1992), psychosocial
acceleration theory appreciated that growing up fast and be-
having in putatively nonoptimal ways was sometimes ad-
vantageous when it came to dispersing genes in future
generations. Although maturing early is known to carry nu-
merous risks for females, including early sexual debut, early
first birth, sexually transmitted disease, and breast cancer
(Ellis, 2004), such “ontogenic risk taking” was theorized to
make biological sense under conditions of adversity. It was
for this reason that Belsky et al. (1991) proposed that rearing
conditions that induced in the individual the sense that the fu-
ture was risky and that supportive relationships were precar-
ious would promote early maturation, early sexual debut, pro-
miscuous sexual behavior, unstable pair bonds, limited
parental investment, and the bearing of more rather than fewer
offspring. After all, from the standpoint of reproductive fit-
ness, it is better to “live fast and die young,” having offspring
along the way, than to die (or become disabled) before getting
the chance to reproduce (Chisholm, 1993; Nettle, 2010).
Thus, adolescents who, for example, respond to dangerous
environments by developing insecure attachments; adopting
opportunistic, advantage-taking interpersonal orientations;
engaging in externalizing behavior; discounting the future;
and experiencing early sexual debut are no less functional
or even less regulated than are those responding to a well-re-
sourced and supportive social environment by developing the
opposing characteristics and orientations (Belsky et al., 1991;
Ellis, Boyce, et al., 2011).
What this analysis highlights is that development involves
trade-offs, a concept central to an evolutionary, life-history
perspective. As just noted, a primary risk associated with
waiting to mature, find a mate, and breed is that one may
not survive long enough to achieve any or all of these ends.
Additional risks include limits to ones’ capabilities and com-
petencies, as well as poor health, thereby making it difficult to
attract mates and/or protect and facilitate the development of
the offspring one eventually produces. Ellis and associates (in
press) recently pointed out in this regard that the concept of
allostatic load, which informs ever more developmental in-
quiry (e.g., Evans & Kim, 2012; Fuller-Rowell, Evans, &
Ong, 2012), may need rethinking. Instead of conceptualizing
this construct as part of a disease process, it could be better to
think of it in terms of evolutionary and life-history trade-offs.
Although there are indisputable costs associated with devel-
oping in certain ways under conditions of ecological stress,
costs that seem to undermine child well-being, long-term
health and even longevity, these costs may be compensated
for by the increased likelihood that the individual incurring
these costs would make it to maturity, find a mate, and pro-
duce offspring.
It is intriguing that the aforementioned rodent work once
again proves consistent with the view just advanced: life
conditions can regulate the rate of development in the service
of fitness goals. Moreover, this is because it is not true that
stressful rearing conditions that take the form of limited ma-
ternal licking of the rat pup increase fearful and defensive be-
haviors via the epigenetic regulation of the stress-response
system. All too unappreciated by many developmentalists
who (appropriately) herald this work for its documentation
of such effects is that such putatively limited maternal care
also accelerates sexual maturation, increases sexual behavior,
and reduces parental investment. It would appear then that pa-
rental “neglect” in the form of limited licking and grooming
serves as a means of regulating (not dysregulating) develop-
ment in a biologically strategic manner. This is consistent
with Belsky et al.’s (1991) psychosocial acceleration theory,
as noted by Cameron and associates (2005). In this rodent
context, neglect can be regarded as a mechanism through
which rat mothers facilitate their offspring’s development
by accelerating it toward survival and reproductive strategies
that are optimal under conditions of adversity. Therefore, it
would seem mistaken to view diminished licking and groom-
ing as “poor maternal care” or the development induced by
such care as disturbed, dysregulated, or nonoptimal. From
an evolutionary perspective, the care provided by the puta-
tively neglectful parents may serve as appropriate preparation
J. Belsky and M. Pluess1246