660 vI. SELF‑ AND S OCIAL P ROCESSES
tachment. One way to improve research 
on socialization is by using genetically in -
formed designs that provide a way to tease 
apart nature and nurture (e.g., Roisman & 
Fraley, 2006). Regardless of whether one as -
sumes that genes influence attachment, one 
can use genetically informed designs to con -
duct powerful research on environmental 
influences.
Finally, we believe that the integration of 
these research traditions provides an excit -
ing way to bridge research on personality 
and attachment. Most discussions of the eti -
ology of personality employ behavior genet -
ics methods under the assumption that the 
question of how  people came to be who they 
are boils down to “born that way” versus 
“not born that way.” We believe that attach -
ment theory provides a rich developmental 
legacy to serve as an excellent test case for 
understanding how genetic and environmen -
tal explanations can be integrated, tested, 
and used to advance knowledge of person -
ality development. But to be successful, this 
enterprise requires investments from schol -
ars with expertise in multiple areas, includ -
ing behavior genetics, personality, develop -
ment, and attachment.
What Is the  Relation between  Attachment 
and Trait  Constructs?
One pressing issue for researchers working 
at the interface of attachment and personal -
ity is the association, both conceptual and 
empirical, between individual differences in 
attachment and personality traits, such as 
the Big Five dimensions (e.g., John, Chapter 
2, this volume). Theoretically, the issue is 
not as clear-cut as some might wish. Bowl -
by (1973, p. 369) explicitly argued that a 
child’s preexisting dispositions play a role in 
his or her responses to the environment; in 
some respects, they are responsible for the 
shape of the epigenetic stage upon which 
attachment relationships play out. But he 
also argued that the history of interactions 
between a child and his or her attachment 
figures is the more proximate and crucial 
determinant of the thoughts, feelings, and 
behaviors that the child’s experiences in 
close relationships, regardless of the preex -
isting dispositions upon which they are lay -
ered.In the lingo of contemporary personal -
ity psychology, it is unclear from Bowlby’s 
writings whether he considered basic per -
sonality traits to be independent predic -
tors of interpersonal behavior, the starting 
point in a mediated casual chain, a potential 
moderator of the relations between attach -
ment and interpersonal behavior, or some 
combination of the above. Regardless, it is 
certain that Bowlby did not conceptualize 
individual differences in security as being 
“nothing more” than preexisting personali -
ty traits. In that spirit, it is worth noting that 
there has been a great deal of research over 
the past decade examining how individual 
differences in security predict various out -
comes, after researchers statistically control 
for individuals’ scores on measures of basic 
personality traits, such as neuroticism. For 
example, there is robust evidence that the 
relationships of secure individuals tend to 
be more stable than those of insecure people 
(either anxious or avoidant). Secure people 
also report higher levels of relationship sat -
isfaction and adjustment relative to insecure 
people (see Mikulincer & Shaver, 2016, for 
a review). This pattern has been consistently 
obtained in studies of both dating and mar -
ried couples and cannot be explained by 
other personality factors, such as the Big 
Five personality traits or self-  esteem (Noftle 
& Shaver, 2006). Moreover, research on 
seemingly basic affective responses reveals 
that measures of attachment predict emo -
tional reactions even when basic personality 
traits are controlled (e.g., Erez, Mikulincer, 
Van IJzendoorn, & Kroonenberg, 2008; Mi -
kulincer, Gillath, & Shaver, 2002).
Despite the fact that individual differenc -
es in attachment are related to a variety of 
outcomes when basic personality traits are 
controlled, it is important to note that at -
tachment and personality traits are  related 
to one another in meaningful ways. Attach -
ment anxiety, not surprisingly, is substan -
tially correlated with neuroticism ( r’s in the 
.40–.50 range), and avoidant attachment is 
often negatively correlated (e.g., r ’s around 
–.20) with agreeableness and extraversion 
(see Noftle & Shaver, 2006, for a detailed 
review). As a result, the core individual dif -
ferences in attachment can be located in 
the well-known five-  dimensional space ad -
vocated in much contemporary personality 