Ci a ion: Ba e o-Za za, Flo encia,
and En ique B. A anz-F eijo. 2022.
Family Con ex , Pa en ing and Child
De elopmen : An Epigene ic
App oach. Social Sciences 11: 113.
h ps://doi.o g/10.3390/
socsci11030113
Academic Edi o : Nigel Pa on
Recei ed: 31 Oc obe 2021
Accep ed: 4 Ma ch 2022
Published: 8 Ma ch 2022
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Family Con ex , Pa en ing and Child De elopmen :
An Epigene ic App oach
Flo encia Ba e o-Za za 1,2,* and En ique B. A anz-F eijo 1,2,*
1Facul y o Psychology, Uni e si y o he Basque Coun y UPV/EHU, 20018 San Sebas ian, Spain
2Biodonos ia Heal h Resea ch Ins i u e, 20014 San Sebas ian, Spain
*Co espondence: lo [email p o ec ed] (F.B.-Z.); [email p o ec ed] (E.B.A.-F.)
Abs ac :
This pape p esen s an essay ha uses an epigene ic app oach o a ain an inclusi e and
in-dep h unde s anding o he in luence o amily con ex and quali y o pa en ing on child en’s
psychological de elopmen . Based on he iden i ica ion o a key de elopmen al p ocess in which
in e ac ions a e con inuously in e nalised, he app oach d aws a en ion o he bidi ec ional and
sys emic na u e o in a amily and pa en ing in e ac ions and highligh s he mul iple ac o s ha
in luence hem, which a e linked o he de elopmen al his o y o he species, he indi idual cha ac-
e is ics o bo h he child and hei pa en s, and con ex ual a iables. In esponse o hese in e nalised
in e ac ions, he body ac i a es epigene ic mechanisms, such as DNA me hyla ion, which may a ec
he pheno ypic exp ession o he genome. Theo e ical and me hodological implica ions a e discussed
in ligh o he cu en p ocess o iden i ying he biological p o iles unde lying nega i e and posi-
i e pa en ing p ac ices. Some insigh s a e o e ed ega ding he challenges and oppo uni ies ha
pa en s and policymake s should add ess in he 21s cen u y in connec ion wi h he p omo ion o
posi i e pa en ing, aking in o accoun he epigene ic p ocesses igge ed by ad e se en i onmen s
o child en and hei amilies.
Keywo ds: pa en –child in e ac ions; pa en ing; ea ly childhood de elopmen ; epigene ics
1. In oduc ion
The main objec i e o his essay is o suppo he use o an epigene ic app oach as
a means o gaining an inclusi e and in-dep h unde s anding o he in luence o amily
con ex and quali y o pa en ing on child en’s psychological de elopmen . New e idence
in he ield o neu oscience sugges s ha one way o aking di e en in luences on chil-
d en’s psychological de elopmen in o accoun may be o concep ualise i as an epigene ic
p ocess. Wi hin his app oach, ac o s ha in luence he quali y and quan i y o he amily
in e ac ions expe ienced by he subjec , which in u n s em om indi idual child and
pa en al a iables, as well as om con ex ual a iables such as exposu e o neu o oxins,
s ess and po e y, may gi e ise o molecula p ocesses a ound DNA which, while no
ac ually mu a ing i s s uc u e, ne e heless egula e he ac i i y o he genome, con ig-
u ing he human pheno ype in a mul i ude o di e en ways (Nilsson e al. 2018). These
pheno ypes may e en be ansmi ed h ough in e - and/o ansgene a ional inhe i ance
(Yeshu un and Hannan 2019).
The main b eak h ough o ecen yea s is he iden i ica ion o molecula ac o s and
p ocesses a ound DNA ha egula e genome ac i i y independen ly om he DNA se-
quence (Nilsson e al. 2018). O hese molecula p ocesses, DNA me hyla ion is he one
ha has been s udied mos ; i consis s o he addi ion o a molecule o me hyl g oup nea
o inside he gene p omo e o in si es whe e gene ansc ip ion is ini ia ed. Me hyla ion
al e s he egula o y egions o he genes, which in u n igge s hei un imely ac i a ion o
deac i a ion, he eby gi ing ise o diso de s and diseases (Yeshu un and Hannan 2019). As
Nilsson e al. (2018) poin ed ou , o he epigene ic p ocesses include his one modi ica ion,
Soc. Sci. 2022,11, 113. h ps://doi.o g/10.3390/socsci11030113 h ps://www.mdpi.com/jou nal/socsci
Soc. Sci. 2022,11, 113 2 o 13
RNA noncoding and RNA me hyla ion, he complex in eg a ion o epigene ic modi ica ions
in o gene disposi ion ha esul s in wha is called he epigenome.
Once he gene al ounda ions o he epigene ic app oach a e in oduced, he key o
unde s anding he p oposal made by his essay is o bea in mind ha he in e ac ions
occu ing inside he amily sys em a e in luenced by many di e en a iables, including
pa en s’ and child en’s indi idual a iables, which will be discussed in Sec ion 2, and
con ex ual a iables, which will be discussed in Sec ion 3. Gi en he ex ensi e li e a u e
published ecen ly showing he links be ween amily con ex , pa en ing and epigene ic
p ocesses, Sec ion 4will be de o ed o explo ing he indings epo ed in ha ield. Finally,
in Sec ion 5, he heo e ical and me hodological implica ions o he p oposed epigene ic
app oach will be discussed, paying special a en ion o oppo uni ies and challenges o
pa en s and pa en ing science in he 21s cen u y. Figu e 1p o ides a schema ic ou line o
he essay’s o ganisa ion, a ionale and s uc u e.
Soc. Sci. 2022, 11, x FOR PEER REVIEW 2 o 13
2019). As Nilsson e al. (2018) poin ed ou , o he epigene ic p ocesses include his one mod-
i ica ion, RNA noncoding and RNA me hyla ion, he complex in eg a ion o epigene ic
modi ica ions in o gene disposi ion ha esul s in wha is called he epigenome.
Once he gene al ounda ions o he epigene ic app oach a e in oduced, he key o
unde s anding he p oposal made by his essay is o bea in mind ha he in e ac ions
occu ing inside he amily sys em a e in luenced by many di e en a iables, including
pa en s’ and child en´s indi idual a iables, which will be discussed in Sec ion 2, and
con ex ual a iables, which will be discussed in Sec ion 3. Gi en he ex ensi e li e a u e
published ecen ly showing he links be ween amily con ex , pa en ing and epigene ic
p ocesses, Sec ion 4 will be de o ed o explo ing he indings epo ed in ha ield. Fi-
nally, in Sec ion 5, he heo e ical and me hodological implica ions o he p oposed epige-
ne ic app oach will be discussed, paying special a en ion o oppo uni ies and challenges
o pa en s and pa en ing science in he 21s cen u y. Figu e 1 p o ides a schema ic ou -
line o he essay’s o ganisa ion, a ionale and s uc u e.
Figu e 1. Rep esen a ion o he epigene ic app oach o unde s anding psychological de elopmen
as a p oduc o in e nalised in e ac ions, which a e in luenced by indi idual pa en and child a i-
ables, as well as by con ex ual a iables.
2. Indi idual Pa en and Child Va iables Tha Con ibu e o Family Bidi ec ional In-
e ac ions
The in luence o amily bidi ec ional in e ac ions can be analysed wi hin he ame-
wo k o he law o double o ma ion o highe psychological p ocesses (Vygos ky 1962),
which posi s ha all highe psychological unc ions appea wice: i s in he social ield,
a an in e psychological le el, and la e a he in apsychological indi idual le el. Wi hin
his app oach, psychological de elopmen is iewed as he esul o he in e nalised in e -
ac ions ha make up e e y human being’s indi idual p o ile. I is impo an o highligh
he ac ha hese in e ac ions may also be he consequence o sel - egula ion p ocesses,
which a e based on he exchange o in o ma ion be ween di e en pa s o he amily sys-
em and a e cha ac e is ic o complex sys ems (Von Be alan y 1968; Minuchin 1988). The
sys emic sel - egula ion p ocess ha akes place in he amily con ex , which is ob iously
bidi ec ional in na u e, is illus a ed, o example, by pa en s’ e o s o ensu e exclusi e
in e ac ion momen s wi h hei i s bo n child as a means o compensa ing o he jealous
beha iou ha said child may exhibi in esponse o he bi h o a new sibling.
The classic sys emic app oach has e ol ed owa ds a complex model o unde s and-
ing de elopmen , which was e med “de elopmen sys ems heo y” by G i i hs and S o z
(2018). These au ho s iden i y epigene ics and de elopmen al dynamics as key concep s
o unde s anding de elopmen as a p ocess o change ha con inues h oughou he li e
cycle, a he han as a me e se o in e ac ions be ween in luencing a iables. Gu alnick
Figu e 1.
Rep esen a ion o he epigene ic app oach o unde s anding psychological de elopmen as
a p oduc o in e nalised in e ac ions, which a e in luenced by indi idual pa en and child a iables,
as well as by con ex ual a iables.
2. Indi idual Pa en and Child Va iables Tha Con ibu e o Family
Bidi ec ional In e ac ions
The in luence o amily bidi ec ional in e ac ions can be analysed wi hin he amewo k
o he law o double o ma ion o highe psychological p ocesses (Vygos ky 1962), which
posi s ha all highe psychological unc ions appea wice: i s in he social ield, a an
in e psychological le el, and la e a he in apsychological indi idual le el. Wi hin his
app oach, psychological de elopmen is iewed as he esul o he in e nalised in e ac ions
ha make up e e y human being’s indi idual p o ile. I is impo an o highligh he ac
ha hese in e ac ions may also be he consequence o sel - egula ion p ocesses, which
a e based on he exchange o in o ma ion be ween di e en pa s o he amily sys em
and a e cha ac e is ic o complex sys ems (Von Be alan y 1968;Minuchin 1988). The
sys emic sel - egula ion p ocess ha akes place in he amily con ex , which is ob iously
bidi ec ional in na u e, is illus a ed, o example, by pa en s’ e o s o ensu e exclusi e
in e ac ion momen s wi h hei i s bo n child as a means o compensa ing o he jealous
beha iou ha said child may exhibi in esponse o he bi h o a new sibling.
The classic sys emic app oach has e ol ed owa ds a complex model o
unde s anding de elopmen , which was e med “de elopmen sys ems heo y” by
G i i hs and S o z (2018). These au ho s iden i y epigene ics and de elopmen al dynamics
as key concep s o unde s anding de elopmen as a p ocess o change ha con inues
h oughou he li e cycle, a he han as a me e se o in e ac ions be ween in luencing
a iables. Gu alnick (2011) sums up he dynamic de elopmen al sys ems model by o mu-
la ing he exis ence o amily pa e ns o in e ac ion ha os e child en’s comp ehensi e
Soc. Sci. 2022,11, 113 3 o 13
de elopmen , and which in u n depend on he accommoda ions made wi hin he amily
sys em o adap o he child’s de elopmen al peculia i ies and beha iou s, he eby gen-
e a ing ongoing bidi ec ional in e ac ions. In he ollowing pa ag aphs, e idence linked
o a iables ha in luence he in e ac i e p ocess ou lined abo e will be explained. These
a iables may be gene ic-an h opological in na u e, i.e., cha ac e is ic o all membe s o he
species, o hey may be speci ic o each indi idual and indica i e o he di e si y obse ed
among bo h child en hemsel es and hei pa en s o p incipal ca egi e s.
In ela ion o gene ic-an h opological a iables, i is impo an o highligh he im-
ma u i y speci ic o he human species (sapiens-sapiens). As B une (1972) poin s ou , i
is p ecisely upon he imma u i y o newbo n humans ha he possibili y o educa ion
depends, since his imma u i y esul s in a neu ological plas ici y open o he cons an
es ablishmen o new neu al connec ions as a consequence o di e se expe iences, lea ning
and in e ac ions. One example o his is he concep ualisa ion o he ypes o a achmen
desc ibed by he scien i ic li e a u e (Bowlby 1962;Ainswo h 1979) as di e en ial pheno-
ypical ou comes esul ing om di e en in e ac i e p ocesses, which e en ually lead o
he c ys allisa ion o secu e, insecu e o diso ganised a achmen ypes.
The idea ou lined in he p e ious pa ag aph is compa ible wi h a key app oach in ou
cu en unde s anding o psychological de elopmen , namely e olu iona y de elopmen al
psychology. Bjo klund (2018b) a gues ha ou long pe iod o imma u i y, which he de-
sc ibes as he in en ion o childhood by he species sapiens sapiens, lies a he hea o hose
cogni i e skills conside ed o be exclusi ely human. Gi en he de elopmen al impo ance
o his pe iod o imma u i y and plas ici y, which is so cha ac e is ic o he human species,
i could be said ha he gene ic inhe i ance o each membe o ha species is exac ly he op-
posi e o gene ic de e minism, since i e lec s hei neu ological openness o he in luence
o con ex ual a iables, which lea e hei ma k on each indi idual’s epigenome h ough
he in e ac ion in e nalisa ion p ocess. Bjo klund (2018a) also poin s ou he po en ial o he
epigene ic app oach as a concep ual amewo k ha b ings oge he all ou accumula ed
knowledge abou child en’s psychological de elopmen .
Piage ’s gene ic epis emology heo y (Piage 1976) also i s in o he con ex o gene ic-
an h opological a iables, due o he mechanism o adap a ion h ough play and imi a ion.
Piage (1976) iewed hese wo mechanisms—play and imi a ion—as a modus ope andi spe-
ci ic o ou species ha in luences child en’s in e ac ions wi h he su ounding en i onmen
and is pa o ou gene ic bluep in and highly sensi i e o en i onmen al in luences. When
his au ho e e s o “assimila ion” as a componen o he adap i e p ocess, he sugges s
ha i is beha iou ally ep esen ed h ough play, unde s ood as a epe i i e, eassu ing
ac i i y designed o consolida e cogni i e and pleasu e s uc u es. “Accommoda ion” is
beha iou ally ep esen ed h ough imi a ion, an ac i i y ha seeks o in eg a e new ideas
and is lexible by na u e and i al o igge ing de elopmen al c ises wi hin he cogni i e
s uc u e. In ela ion o play, he clinical epo published by he Ame ican Academy o
Pedia ics (Yogman e al. 2018) is wo h men ioning, since i highligh s he ole o play
in cogni i e de elopmen . Wi h ega d o imi a ion, esea ch in o i s impac on cogni i e
de elopmen con inues o be a ele an ield o s udy oday (Heyes 2016).
A u he le el o analysis, which was men ioned ea lie in he in oduc ion o his
second sec ion, e e s o he in luence o child en’s indi idual cha ac e is ics on pa en ing
in e ac ions. These in luences enable us o unde s and why, when exposed o expe iences
ha may al e he sou ce o de elopmen (such as poo pa en ing), some indi iduals
achie e no malised de elopmen while o he s de elop maladap i e symp oms o e ime.
In his sense, Calkins e al. (2013) p opose ha esponses o exposu e o ce ain expe iences
may be in luenced by he human geno ype. Child en’s indi idual cha ac e is ics include
empe amen , unde s ood as an indi idual’s deg ee o eac i i y (Ro hba e al. 2000); child
empe amen is an indi idual cha ac e is ic ha has a clea impac on pa en al eac ions
o hei child en’s beha iou . In his sense, A mou e al. (2018) ound ha , du ing
ea ly childhood, child en’s i i abili y and ea we e associa ed wi h pa en al coe cion
(ex e nal con ol) and o e p o ec ion, espec i ely. The in luence o empe amen is also
Soc. Sci. 2022,11, 113 4 o 13
e iden in a s udy by Xuan e al. (2018), who ound ha among child en wi h a s ong
empe amen , cha ac e ised by high nega i e emo ionali y, pa en al s ess was mo e likely
o ha e a nega i e e ec on de elopmen . Fo hei pa , Jousseme e al. (2008) ound
ha ha ing a eac i e empe amen and being a boy we e wo a iables associa ed wi h a
g ea e use o physical agg ession by pa en s, and Bake and Milligan (2016) also obse ed
gende di e ences in ela ion o pa en al ea men . In his second s udy, he au ho s
ound ha gi ls bene i ed om a g ea e ime in es men by pa en s in lea ning ac i i ies
such as eading. These indings suppo he idea ha some cha ac e is ics, such as sex o
empe amen , may ac as il e s ha in luence and mode a e pa en ing p ac ices du ing
he de elopmen al p ocess, and e eal he bidi ec ional na u e o he in luences wo king
wi hin he amily sys em.
In ela ion o he indi idual pa en al a iables ha may a ec he quali y o bidi-
ec ional in e ac ions, one ac o o bea in mind is he possible epigene ic ansmission
o pa en ing p ac ices. Childhood expe iences may cause dis up ions in ce ain neu al
ci cui s, which a e la e necessa y du ing adul hood in o de o enable he indi idual o
espond app op ia ely o hei child’s signals. These expe iences may he e o e esul in
modi ica ions o he epigenome ha may be ansmi ed o o sp ing (Feldman 2017). In
his sense, Lomanowska e al. (2017) highligh he ac ha ad e se expe iences du ing
ea ly childhood may al e he de elopmen o he execu i e unc ions equi ed o he
sel - egula ion o pa en ing beha iou du ing adul hood.
Ano he s udy wo h men ioning is ha ca ied ou by Riem e al. (2012), who used
unc ional magne ic esonance imaging o show ha , in esponse o in an c ying, adul s
wi h insecu e a achmen ep esen a ions had heigh ened amygdala ac i a ion, el mo e
i i a ed and g ipped a handg ip wi h mo e o ce han hose wi h secu e a achmen
ep esen a ions. The au ho s concluded ha he hype ac i a ion o he amygdala may
explain why people wi h insecu e a achmen pa e ns expe ience eelings o a e sion and
ange in esponse o in an c ying, esponding inconsis en ly o in an signals and ailing o
engage in beha iou s ha would acili a e he es ablishmen o secu e a achmen . This
same pa e n o beha iou was also obse ed in he s udy by Ma in e al. (2018), who
ound ha hose who had expe ienced highe le els o ma e nal sensi i i y du ing he i s
h ee and a hal yea s o li e made ewe nega i e causal a ibu ions abou in an c ying
h ee decades la e , and exhibi ed g ea e igh -co ex eac i i y in esponse o he s imulus,
he eby pe mi ing he ac i a ion o a esponse o in an dis ess. These indings seem
o sugges ha he quali y o in e ac ions du ing ea ly childhood may p edic pa en ing
abili ies du ing adul hood, a beha iou al cycle ha may epea i sel again in he ollowing
gene a ion (Feldman 2017;Kundako ic and Champagne 2015). In o he wo ds, pa en s’
sensi i i y le els may depend on epigene ic changes ha hey inhe i ed om hei own
pa en s, con ibu ing ( o be e o o wo se) o he quali y o ca e hey p o ide o hei
o sp ing (Lomanowska e al. 2017).
Pa en s’ men al heal h is also a a iable ha may in luence pa en ing in e ac ions and,
he e o e, child en’s wellbeing. S udies ha e shown ha pa en s’ dep essi e symp oms,
s ess and anxie y a e associa ed wi h hei o sp ing’s cogni i e de elopmen le el, in e -
nalising p oblems and beha iou al p oblems du ing ea ly childhood (Keyse e al. 2017;
Reupe and Maybe y 2016). Simila ly, du ing he eenage yea s, pa en s’ psychopa hologi-
cal symp oms ha e also been linked o adolescen s’ subs ance abuse (Bu s ein e al. 2012)
and low le els o social compe ence (Vallo on e al. 2016). In gene al e ms, psychia ic
diso de s may inhibi adul ca e s’ abili y o espond app op ia ely o hei child en’s
signals and p o ide lea ning oppo uni ies o os e heal hy psychological de elopmen in
di e se ields.
3. Con ex ual Va iables Tha Con ibu e o Family Con ex and Pa en ing In e ac ions
This sec ion desc ibes he wo concep ual amewo ks mos widely accep ed by he
scien i ic communi y in he ield o de elopmen al psychology o classi ying con ex ual
a iables. The i s is B on enb enne ’s bioecological heo y (B on enb enne 2001), which
Soc. Sci. 2022,11, 113 5 o 13
posi s ha de elopmen occu s as a esul o in e ac ions be ween an ac i e indi idual and
hei mos immedia e con ex , called he mic osys em. This p ocess may also be a ec ed
by he ela ionships es ablished be ween his mos immedia e en i onmen and b oade
con ex s, concei ed as ou in e connec ing ings: he mic o, meso, exo and mac o sys-
ems. The amily mic osys em is he con ex in which pa en ing in e ac ions ake place
in a s able and sus ained manne . Du ing he ea ly yea s o li e, he b ain is pa icula ly
sensi i e o hese in e ac ions, which may in luence hose b ain ci cui s ha enable cog-
ni i e de elopmen , language, sel - egula ion and social compe ence (Nelson e al. 2019;
Lomanowska e al. 2017;Kundako ic and Champagne 2015).
Since child en’s i s expe iences ake place in he amily en i onmen , pa en ing com-
pe ence is a key a iable in he sensi i e pe iods ha occu du ing di e se de elopmen al
(cogni i e, linguis ic, emo ional and social) p ocesses (Zheng e al. 2018). Ne e heless,
bidi ec ional in e ac ions may also occu in o he mic osys em con ex s, such as a school
wi h one’s eache and pee g oup. In his sense, he nex ing is he mesosys em, which
e e s o he ela ionship be ween wo o mo e mic osys ems, such as he ela ionship
be ween he amily and he school o he pee g oup. One example would be he ype o
ela ionship ha exis s be ween pa en s and hei child’s eache . A high le el o engage-
men in his sense may esul in ewe beha iou al p oblems and be e academic esul s
(She idan e al. 2019). The mesosys emic analysis o he amily–school ela ionship is
essen ial, o example, in diagnosing and in e ening in cases o school bullying
(Šmigelskas e al. 2018).
The hi d ing desc ibed in bioecological heo y is he exosys em, de ined as all
hose con ex ual a iables in which he indi idual does no ac i ely pa icipa e. This
le el includes a iables ha a e no pu ely in e ac i e in na u e bu a ec he quali y o
he pa en ing in e ac ions o which he indi idual is exposed. When cha ac e ising he
exosys em, i is impo an o highligh he exis ence o a iables ha in luence psychological
de elopmen h ough di e en pa hways. Fo example, s ess is a a iable ha may a ec
de elopmen di ec ly, such as in cases in which child en a e exposed o po e y, li e wi h
a subs ance-abusing adul , ha e no esponsible ca egi e able o espond o hei needs
and/o a e wi nesses o ongoing si ua ions o iolence (Shonko 2015). Fu he mo e, a
s ess ul si ua ion expe ienced by a pa en , whe he i be in he amily en i onmen o in an
ex e nal con ex such as a wo k, may indi ec ly a ec he quali y o pa en ing in e ac ions,
esul ing in he use o coe ci e discipline, hos ili y, less sensi i i y o he child’s signals
and/o less engagemen in lea ning ac i i ies, among o he s.
While being quali a i ely di e en , bo h o he si ua ions desc ibed abo e ne e heless
gene a e epigene ic changes in he epigenome ha in u n a ec gene exp ession. This
si ua ion may cause dis up ions in he b ain, a ec ing neu one s uc u e, and consequen ly,
psychological de elopmen (Chen and Ba am 2016). The exosys em ing may include
e en mo e quali a i ely di e en a iables, such as hose ha di ec ly a ec de elopmen ,
e.g., exposu e o neu o oxic con aminan s in he ai , wa e o ood (Gascon e al. 2017);
o o he s, such as pa en s’ educa ion le el o socioeconomic s a us, which while no
being s ic ly in e ac i e in na u e ne e heless a ec he quali y o ela ionships indi ec ly
(Mey ose e al. 2018).
The nex ing in he bioecological app oach is he mac osys em. This le el encom-
passes hose a iables loca ed wi hin he ins i u ional con ex in which he indi idual
li es, and includes cul u e, belie s, alues, eligion and he poli ical, social and educa-
ion sys ems. The mac osys em co e s child p o ec ion policies and posi i e pa en ing
ini ia i es aimed a os e ing condi ions ha could ha e a signi ican e ec on he psycho-
logical de elopmen p ocess. Some such measu es include Recommenda ion 19 o he
Commi ee o Minis e s o he Council o Eu ope (2006) o membe s a es on policy o
suppo posi i e pa en ing, measu es adop ed a a local le el o assess amily con ex s
and design p e en ion p og ammes ocusing on posi i e pa en ing, wo k–li e balance
measu es, b eas eeding suppo plans, p omo ing he use o g een spaces (which has been
linked o be e men al heal h and cogni i e de elopmen ) and he con ol o en i onmen-
Soc. Sci. 2022,11, 113 6 o 13
al pollu an s, among o he s (Gascon e al. 2017). Thus, he model which unde s ands
de elopmen as an epigene ic p ocess complemen s B on enb enne ’s bioecological heo y,
while a he same ime p o ing consis en wi h eali y, since i is an open model ha aims o
ecognise all hose a iables iden i ied in he li e a u e as ha ing an in luence on child en’s
psychological de elopmen .
The second concep ual amewo k o en used o classi y he con ex ual a iables in-
luencing he in e ac ions ha con ibu e o he epigene ic p ocess s ems om he ield o
beha iou al gene ics and is known as nonsha ed en i onmen s (Plomin 2014). Unlike he
opposi e concep o sha ed en i onmen s, nonsha ed en i onmen s e e o all hose exclu-
si e in e ac ions ha ake place wi h each amily membe . One example o his exclusi e
ype o in e ac ion is ha p o ided by Jenkins e al. (2016), who p opose he exis ence o
di e en ial pa en ing, which s ems om bo h pa en e ec s and child e ec s and is de ined
as he di e en ea men ecei ed by siblings wi hin he same amily sys em. The ind-
ings epo ed in hei s udy sugges ha he c ea ion o di e en spaces wi hin he amily
con ex may lead o clea ly di e en de elopmen pa hways. Disc imina o y di e en ial
ea men , based on a ou i ism and compa isons be ween siblings as a pa en ing esou ce,
is nega i ely associa ed wi h child en’s wellbeing (Zheng e al. 2018). Mo eo e , siblings
who a e subjec o disc imina o y di e en ial ea men epo a highe le el o nega i i y
in he quali y o hei sibling ela ionships (Jenkins e al. 2016).
The concep o nonsha ed en i onmen s was consolida ed by s udies wi h iden ical
wins, which ound ha epigene ic in luences in DNA s uc u e can be a ibu ed o he
di e en expe iences o which each win is exposed wi hin he same amily en i onmen
(Plomin 2014). In a ecen s udy in ol ing 4718 wins aged be ween 7 and 12 yea s,
Zheng e al. (2018) iden i ied six subg oups wi h di e en cogni i e de elopmen pa e ns
( e bal and non e bal in elligence). The au ho s ound ha he in luence o nonsha ed
en i onmen s was pa icula ly s ong among hose g oups whose cogni i e skills had been
obse ed o imp o e. These esul s a e consis en wi h hose o he longi udinal s udy
ca ied ou by F ani´c e al. (2014) wi h a sample o 1748 wins aged be ween 5 and 18 yea s.
The au ho s obse ed ha while he s abili y o cogni i e abili ies o e ime was mainly due
o gene ic ac o s, nonsha ed en i onmen s we e he main ac o esponsible o changes in
cogni i e abili y (bo h e bal and non e bal).
4. Family Con ex and Pa en ing In e ac ions Tha Con ibu e o Epigene ic P ocesses
As i was highligh ed in he in oduc ion, epigene ic p ocesses a e c i ical o enabling
o ganisms o espond o hei en i onmen h ough changes in genome exp ession, and
cons i u e a key pa o no mal biology (Nilsson e al. 2018). Today, he e is gene al ac-
cep ance o he concep o “beha iou al epigene ics” (Bjo klund 2018b), which con ains
a ma ked de elopmen al elemen . The analysis ca ied ou by Ci ulli (2021) highligh s
some in e es ing e idence ha shows he con ibu ion made by pa en ing o DNA me hyla-
ion p ocesses and complemen s he abo e-men ioned beha iou al epigene ics app oach.
So-called “ha sh pa en ing” is a a iable ha has a s ong in luence on me hyla ion p o-
cesses; as Bueno (2021) poin s ou , ad e se childhood en i onmen al condi ions, such
as hose gene a ed by ha sh pa en ing, con ibu e o epigene ic modi ica ions ha may
a ec cogni i e and socioemo ional de elopmen . These indings a e also suppo ed by
he wo k o Lewis e al. (2021), which highligh s he in luence o ha sh pa en ing on DNA
me hyla ion (an in luence ha is simila o ha o o he ad e se ea ly expe iences, such
as abuse and neglec ) and iden i ies he HPA diu nal unc ion in NR3C1 gene me hyla-
ion. I is also wo h highligh ing ha , in he ea ly s ages o child de elopmen , ac o s
in luencing he oe us du ing i s in au e ine de elopmen a e g ouped unde he concep
o “ oe al p og amming”. The mos widely s udied nega i e ( e a ogenic) in luences a e
smoking, he consump ion o alcohol and o he d ugs, s ess and exposu e o neu o oxins
(Gascon e al. 2017). The e ec s o hese a iables a e mani es ed in epigene ic mechanisms,
which may esul in low bi h weigh , delayed mo o de elopmen and emo ional and
beha iou al p oblems du ing childhood, among o he s (Woodwa d e al. 2018).
Soc. Sci. 2022,11, 113 7 o 13
In ela ion o he pos na al pe iod, in e indi idual di e ences in pheno ypic exp ession
ha e mainly been s udied in con ex s o isk and ad e se si ua ions. In a ecen s udy by
Ein-Do e al. (2018), ca ied ou wi h a sample o 109 adul s, he au ho s ound a posi i e
associa ion be ween insecu e-a oidan a achmen and epigene ic modi ica ion in e ms
o oxy ocin (OXTR) and glucoco icoid (NR3C1) ecep o -gene me hyla ion. Oxy ocin has
been associa ed wi h beha iou s ha os e he sea ch o social con ac as a bu e ing
esou ce in s ess ul si ua ions (Smi h and Wang 2014), while glucoco icoid is in ol ed
in he unc ioning o he hypo halamic–pi ui a y–ad enal axis, which is also linked o he
s ess- ela ed h ea esponse. Insecu e a achmen , con lic and auma a e pe cei ed as a
cons an h ea du ing ea ly o middle childhood. In such cases, he si ua ion igge s he
p olonged ac i a ion o physiological s ess esponses, which in u n may al e he exp es-
sion o he genome in ol ed in di e se b ain a eas, ul ima ely a ec ing he de elopmen
p ocess (Chen and Ba am 2016). In he absence o a sensi i e adul capable o blocking he
sec e ion o s ess ho mones, child en a e unable o eco e hei no mal physiological s a e
and do no lea n o dis inguish be ween hose si ua ions which a e uly h ea ening
and hose which a e no (Shonko 2015). Consequen ly, he sys em ends up ailing,
becoming ac i a ed unnecessa ily in esponse o mino e en s (Andaloussi e al. 2019;
Xuan e al. 2018).
Ex an empi ical e idence sugges s ha when s ess is p olonged o e ime
du ing c i ical de elopmen al pe iods, i s impac on b ain s uc u e is g ea e
(Chen and Ba am 2016). A good example o his is he esea ch ca ied ou by
Riem e al. (2019), which ound ha un esol ed auma o loss du ing childhood and
he exis ence o psychopa hological indica o s we e all associa ed wi h educed whi e
ma e in he co pus callosum. The au ho s poin ou ha whi e ma e is necessa y o he
co ec ansmission o in o ma ion be ween neu ons, and he co pus callosum is associa ed
wi h gene al measu es o in elligence, p oblem-sol ing and in o ma ion p ocessing. A
la ge body o li e a u e a es s o he ac ha he sus ained sec e ion o co isol, a ho mone
ha is eleased in esponse o s ess ul si ua ions, may a ec he quan i y and quali y o
he synap ic connec ions ha ake place in he p e on al co ex— he hub o he execu i e
unc ions and necessa y o any ype o lea ning, as well as o a aining he app op ia e
le el o sel - egula ion in he cogni i e, emo ional and beha iou al ields (see, o example,
Lomanowska e al. 2017;Kundako ic and Champagne 2015;Shonko 2015).
I is impo an o highligh he ac ha epigene ic modi ica ions a e no only
he esul o nega i e exposu e o isk con ex s; hey a e also a ec ed by posi i e
exposu e o all high-quali y in e ac ions ha ake place in a no mal amily con ex
(Jensen and Champagne 2012). All hose s able in e ac ions a e ansla ed in o pos-
i i e epigene ic mechanisms and se e as p o ec i e ac o s o heal hy de elopmen
(Shonko 2015). In his ega d, i is wo h no ing he wo k o Naumo a e al. (2016), who
ound ha s able, high-quali y mo he –child in e ac ions in non isk con ex s, e alua ed
h ough o sp ing’s pe cep ions a h ee di e en s ages o he de elopmen p ocess (mid-
dle childhood, ea ly adolescence and la e adolescence), esul ed in epigene ic changes
ha , du ing adul hood, we e linked o indi iduals’ psychosocial adjus men . Simila ly,
Kundako ic and Champagne (2015) obse ed ha he quali y o pa en –child in e ac ions
esul ed in epigene ic changes in neu ode elopmen ha may e en ually impac cogni i e,
emo ional and beha iou al unc ioning, a ec ing s ess esponse and sel - egula ion sys-
ems. The e iew by P o enzi e al. (2020) also suppo s he p o ec i e ole o ma e nal
ca egi ing, as a key pa en ing in e ac ion ha is associa ed wi h a ia ions in he DNA
me hyla ion o genes in luencing socioemo ional de elopmen and bu e ing he epigene ic
p ocesses linked o ea ly ad e si y in child en’s li es.
O he e idence ha has eme ged in epigene ic esea ch is linked o changes
ha may be passed on o o sp ing, a ec ing descendan s’ physical and men al
heal h (Nilsson e al. 2018). Recen s udies ha e ound e idence ha suppo s he
idea o a possible c oss-gene a ional ansmission o pa en ing (Fujiwa a e al. 2019;
Kundako ic and Champagne 2015). The esul s epo ed o da e sugges ha expe i-
Soc. Sci. 2022,11, 113 8 o 13
ences ha igge epigene ic changes in he neu ological sys em may also al e he genes o
ce ain ecep o s such as oxy ocin, se o onin and co isol, which in u n may lead o poo
pa en ing du ing adul hood (Fujiwa a e al. 2019). Fo example, Mile a-Sei z e al. (2016)
ound ha pa en s wi h an oxy ocin de iciency a e less likely o seek a ec i e g a i ica-
ion wi h hei child en, hus gi ing ise o less sensi i e in e ac ions. This in u n a ec s
he de elopmen o hese child en, who in adul hood may epea his sequence, he eby
dis up ing subsequen gene a ions also. In his sense, he wo k o Van Aswegen e al.
(2021) suppo s ansgene a ional co a iance in he me hyla ion le els o genes ela ed o
ma e nal and o sp ing s ess egula ion.
One key ques ion in ela ion o he possible ansmission o good o poo pa en -
ing is whe he o no i is possible o inhe i an epigenome ha is pa icula ly suscep-
ible o ce ain pa en al beha iou s. Wha e e he answe , i is impo an o bea in
mind ha he quali y o pa en ing in e ac ions will also be modula ed by a se ies o
amily-con ex a iables, such as pa en s’ educa ion le el, economic si ua ion, social
suppo ne wo k, s ess and he cha ac e is ics o he child hemsel es, among o he s
(Jensen and Champagne 2012). Fo example, li ing unde s ess ul condi ions may ha e a
mo e nega i e impac on hose people wi h a ce ain deg ee o gene ic suscep ibili y o he
dis up ion o neu al sys ems (Andaloussi e al. 2019;Mile a-Sei z e al. 2016). Ne e heless,
o he da a sugges ha hanks o he plas ici y o he human b ain, he consequences o
an ad e se expe ience du ing ea ly childhood may be mi iga ed by good-quali y expe i-
ences du ing la e s ages, which o a ce ain ex en may compensa e o ea lie de ici s
(Jensen and Champagne 2012).
The upda ed epigene ic app oach p oposed in his essay is based on he heo y o
p obabilis ic epigenesis de eloped by Go lieb (Johns on 2015), in which he e m “p oba-
bilis ic” illus a es he mul iple pheno ypic possibili ies ha may esul om combina ions
o di e en a iables. The concep o a psychological de elopmen al pheno ype has also
been explo ed in he wo k o Cox (2013) and Milb a h (2013). The li e a u e e iew e-
ealed empi ical e idence compa ible wi h an epigene ic app oach o ully desc ibing he
con ibu ion o amily con ex and pa en ing in e ac ions o ou unde s anding o human
psychological de elopmen .
5. Conclusions
5.1. Pa en ing Science in he 21s Cen u y: Theo e ical and Me hodological Implica ions
The i s issue o esol e is whe he he con en s and e lec ions ou lined in his es-
say uly suppo he p oposal o use an epigene ic app oach as a uni ying heo e ical
amewo k o gaining a deepe unde s anding o he in luence o amily con ex and
pa en ing on child en’s psychological de elopmen . I epigene ics aims o explain changes
in de elopmen by aking gene ic and con ex ual a iables in o accoun , hen i is only
logical o es ablish he in e ac ions be ween he wo in luences as he basic uni o analysis.
Mo eo e , once he objec o analysis has been es ablished, he nex s ep would be o
iew he p ocess by which in e ac ions a e in e nalised (acco ding o Vygo sky’s heo y)
as an ac i e mechanism. Since e e yone is exposed o exclusi e in e ac ions in di e en
con ex s h oughou he cou se o hei li e, hese in e ac ions esul in di e en indi idual
pheno ypic exp essions. As Beach e al. (2016) poin ou , esea ch in o epigene ics as a
media o o he connec ions be ween amily/communi y p ocesses and a ange o de elop-
men al ou comes is s ill a g owing ield; howe e , i is also ue, as indeed highligh ed by
he abo e-men ioned au ho s, ha he po en ial o de elop impo an insigh s ega ding
mechanisms linking modi iable en i onmen s o biological p ocesses and long- e m heal h
and de elopmen al ou comes is al eady coming in o iew. The e can be no doub ha
his poses an impo an challenge ha pa en ing science will ha e o deal wi h o e he
coming yea s.
While encompassing many di e en in luences, adi ional app oaches such as bioe-
cological heo y ne e heless ha e di icul y including, in a speci ic ing, a iables wi h
e y di e en quali a i e signi icance, such as, o example, exposu e o he emb yo o
Soc. Sci. 2022,11, 113 9 o 13
neu o oxins and child en’s exposu e o des uc i e in e pa en al con lic . The bioecological
app oach also has ouble explaining phenomena such as, o ins ance, he in e gene a ional
ansmission o pa en ing pa e ns. This ansmission ac ually occu s and is undamen ally
epigene ic in na u e, meaning ha i occu s independen ly o indi iduals’ gene ic makeup
and akes place a an ‘epi’ le el, i.e., a le el abo e ha o genes (Un e naeh e e al. 2021).
One poin in a ou o using he epigene ic app oach as a uni ying and inclusi e
amewo k o explaining he in luences o amily con ex and pa en ing on psychological
de elopmen is ha i e o lessly encompasses he concep o nonsha ed en i onmen s as
a de ining concep o all hose speci ic in e ac ions in an indi idual’s li e ha oge he help
explain he in e indi idual di e ences ha a e so cha ac e is ic o human beings, and which
a e mani es ed in each pe son’s unique pheno ypic p o ile. I is e y impo an o highligh
ha ecognising he impac o nonsha ed en i onmen s on child en’s de elopmen in no
way nega es he simul aneous impac o so-called sha ed en i onmen s, which also in e ac
wi h he gene ic bluep in h oughou he de elopmen p ocess. This is especially ele an
when i comes o unde s anding and iden i ying pa en ing p ac ices ha a e common o
he en i e amily sys em and hose ha a e speci ic o each b o he o sis e .
I is wo h highligh ing ha he epigene ic app oach p oposed he e is concep ually
lexible, meaning ha i is a model ha admi s epigene ic changes beyond hose s ic ly
linked o he main p ocess o DNA me hyla ion (Bjo klund 2018a). In his sense, wo le els
o epigene ic p ocesses can be es ablished: ha pe aining o DNA me hyla ion o his one
modi ica ion p ocesses, and ha pe aining o changes in psychological de elopmen
in e ed h ough obse a ion o beha iou al assessmen . One ele an example would be
ha which was p e iously gi en in his essay abou ypes o a achmen , o which we ha e
bo h empi ical e idence based on obse a ion and ce ain indica ions o neu oho mone
co ela es, such as high le els o co isol in child en wi h diso ganised a achmen . Ano he
example would be he s udy by Ein-Do e al. (2018), which demons a es he ela ionship
be ween insecu e-a oidan a achmen and he me hyla ion o oxy ocin and glucoco icoid
ecep o genes. Ne e heless, u he esea ch is equi ed o eplica e hese indings, and
he epigene ic p o ile o each a achmen pa e n desc ibed in he li e a u e needs o be
explo ed, along wi h hose o psychopa hological diso de s and, in gene al, o he condi ions
ha may a ec heal h ou comes.
The nex ele an conclusion ha can be d awn in ela ion o ou p oposal is ha pa -
en ing science in he 21s cen u y is ce ain o ace some se ious me hodological challenges.
The epigene ic app oach equi es esea ch designs ha ake in o accoun he coin luence
o many di e en ac o s on he dependen a iables being s udied in each case, and his
in u n equi es analysis p ocedu es capable o measu ing he bidi ec ional p ocesses de-
sc ibed abo e, as well as he di e en ial in luence o di e en independen a iables on
speci ic dependen a iables. One example would be he mul iple- eg ession analyses
p o ided by s uc u al-equa ion modelling. The s udy o pa en ing is cu en ly a highly in-
e disciplina y ield, and i is now mo e necessa y han e e o es ablish a common wo king
amewo k and esea ch map ha ende s expe imen al ‘mic o’ s udies compa ible wi h
coho s udies seeking o analyse he in luence o many di e en a iables simul aneously.
A he same ime, i is wo h highligh ing he ac ha he epigene ic app oach allows
esea che s o s udy psychological de elopmen a he in aindi idual le el, sea ching o
di e se pheno ypic pa hways, as well as a he in e indi idual le el, compa ing sample
g oups belonging o di e en backg ounds. A common app oach is i al i we a e no o
lose sigh o he complexi y o he p ocess unde s udy.
5.2. Challenges and Oppo uni ies o Pa en s and Policymake s in he 21s Cen u y
P obably he mos impo an conclusion d awn by his essay is ha he p oposed
app oach has eno mous po en ial in he ield o applied science and amily and pa en ing
policies. In his ega d, i is wo h highligh ing se e al o he challenges and oppo uni ies
o pa en s and policymake s ha can be de i ed om his wo k. Fi s ly, he lexibili y and
openness o con ex o he epigene ic model opens he doo s o mul iple p e en i e and/o
