Psychologist Mary Ainsworth devised the Strange Situation procedure
to test the quality of an infant's attachment to his mother. This
explains the procedure,
discusses how babies respond, and
reviews why some children are insecurely-attached
What is a secure attachment?
According to the theories of John Bowlby (1988), a child is
securely-attached if she is confident of her caregiver’s support. The
attachment figure serves as a “secure base" from which the child can
confidently explore the world.
Secure attachment is also associated with
keeping track of the caregiver during exploration,
approaching or touching the caregiver when anxious or distressed;
finding comfort in proximity and contact
And, in the long-term, kids with secure attachments seem to have many advantages - emotional, social, medical, and cognitive.
But how can you know if researchers would classify your own baby as securely attached? How do they actually measure attachment security? How
The original method, developed by the influential
psychologist Mary Ainsworth, is the laboratory procedure called the
“Strange Situation" (Ainsworth et al 1978).
Typically, the Strange Situation tests how babies or young children respond to the temporary absence of their mothers.
Here’s how it works.
The Strange Situation
To test a child’s "attachment style," researchers put the child and
her mother (these studies almost always focus on the mother) alone in an
The room has toys or other interesting things in it, and the mother lets the child explore the room on her own.
the child has had time to explore, a stranger enters the room and talks
with the mother. Then the stranger shifts attention to the child. As
the stranger approaches the child, the mother sneaks away.
After several minutes, the mother returns. She comforts her child and then leaves again. The stranger leaves as well.
A few minutes later, the stranger returns and interacts with the child.
Finally, the mother returns and greets her child.
How children respond to the Strange Situation
As suggested by its name, the Strange Situation was designed to
present children with an unusual, but not overwhelmingly frightening,
experience (Ainsworth et al 1978). When a child undergoes the Strange
Situation, researchers are interested in two things:
1. How much the child explores the room on his own, and
2. How the child responds to the return of his mother
Typically, a child’s response to the Strange Situation follows one of four patterns.
Securely-attached children: Free exploration and happiness upon mother’s return
The securely-attached child explores the room freely when Mom is
present. He may be distressed when his mother leaves, and he explores
less when she is absent. But he is happy when she returns. If he cries,
he approaches his mother and holds her tightly. He is comforted by being
held, and, once comforted, he is soon ready to resume his independent
exploration of the world. His mother is responsive to his needs. As a
result, he knows he can depend on her when he is under stress (Ainsworth
et al 1978).
Avoidant-insecure children: Little exploration and little emotional response to mother
The avoidant-insecure child doesn’t explore much, and he doesn’t show
much emotion when his mother leaves. He shows no preference for his
mother over a complete stranger. And, when his mother returns, he tends
to avoid or ignore her (Ainsworth et al 1978).
Resistant-insecure (or “ambivalent")
children: Little exploration, great separation anxiety, and ambivalent
response to mother upon her return
Like the avoidant child, the resistant-insecure child doesn’t explore
much on her own. But unlike the avoidant child, the resistant child is
wary of strangers and is very distressed when her mother leaves. When
the mother returns, the resistant child is ambivalent. Although she
wants to re-establish close proximity to her mother, she is also
resentful—even angry—at her mother for leaving her in the first place.
As a result, the resistant child may reject her mother’s advances
(Ainsworth et al 1978).
Disorganized-insecure children: Little exploration and confused response to mother.
The disorganized child may exhibit a mix of avoidant and resistant
behaviors. But the main theme is one of confusion and anxiety. (Main and
Solomon 1986). Disorganized-insecure children are at risk for a variety
of behavioral and developmental problems.
What causes insecure attachments?
Parenting behavior and parenting style
Although parenting alone doesn’t determine your child’s attachment status, it plays a very important role.
In general, secure attachments are associated with
sensitive, responsive parenting.
Insecure attachments are usually attributed to parenting styles that are less sensitive and/or less responsive:
children tend to have parent(s) who are emotionally unavailable or
rejecting. In theory, the child learns that his parent(s) will not
respond to his emotional needs. As a result, he gives up on trying to
signal his needs. The avoidantly-attached child is relatively common in
Western Europe (van IJzendoorn and Kroonenberg 1988; see below). This
prevalence of avoidant attachments may reflect traditional Western
European child-rearing values, which de-emphasize physical contact and
discourage parents from comforting children who cry (e.g., Suizzo 2002;
Compared to avoidantly-attached kids,
resistant-insecure children may have parent(s) who are more emotionally
demonstrative. However—according to popular theory—these parents tend to
be inconsistent, and they aren’t particularly sensitive. They offer
comfort on their own terms, rather than according to a child’s needs.
suggest that disorganized attachment is linked with frightening
maternal behavior, like suddenly looming over a baby’s face (see David
and Lyons-Ruth 2007 for summary). Disorganized attachment may also be
associated with mothers who are themselves frightened (Main and Hess
1990). In addition, children who are abused or neglected are more likely
to suffer from disorganized attachment (Barnett et al 1999).
Like adults, infants differ in temperament, and these temperamental
differences might play a role in the development of an infant’s attachment
relationships (Fuertes et al 2006; Seifer at al 1992). For instance, when researchers tested oxytocin levels in 18 newborns, they found that babies with higher oxytocin levels were more likely to solicit parental soothing and show greater interest in social interaction (Clark et al 2013). Perhaps it's easier for such babies to learn that they have a secure base. By the same token, infants who are
“difficult," or more reactive to stressful situations, may require higher levels of parental responsiveness to develop secure attachments (van den Boom 1994).
In theory, stress could cause insecure attachment by
interfering with a child’s ability to perceive and interpret his
mother’s behavior. Stress could also make it difficult for a child to
select the most appropriate, healthy response to being separated from,
and reunited with, her mother (Waters and Valenzuela 1999).
Environmental stressors—like poor nutrition—may therefore be responsible
for high rates of insecure attachment among some populations (like
impoverished Chilean children, see below).
Studies have reported links between disorganized-insecure
attachment and the variants of several genes, including the dopamine D4 receptor gene (e.g., Lakatos et al
2000). The pattern makes sense if these polymorphisms render the brain less sensitive to neurotransmitters that make friendly social
interactions feel pleasurable. Affected babies would be less motivated to seek comfort from their caregivers, and therefore less likely to develop secure attachments. But do the data tell us a clear story? Not yet. As of 2013, researchers have failed to replicated key findings (Roisman et al 2013).
What about cultural differences?
International studies of the Strange Situation
In studies recognizing three attachment classifications (secure,
avoidant-insecure, and resistant-insecure), about 21% of American
infants have been classified as avoidant-insecure, 65% as secure, and
14% as resistant-insecure. The same distribution is found when researchers pool the results of studies conducted worldwide (van Ijzendoorn and Kroonenberg 1988).
there are local variations. A study conducted in Bielfeld, Germany has reported relatively high
rates of avoidantly-attached infants (52%--Grossman et al 1981). And research conducted elsewhere--in Indonesia, Japan, and the kibbutzim of
Israel—has reported relatively high rates of resistantly-attached
infants (Zevalkink et al 1999; van IJzendoorn and Kroonenberg 1988).
recognizing a fourth classification--disorganized attachment--also vary
by local population. The prevalence of disorganized attachment among
middle class, white American children is about 12% (Main and Solomon
1990). Among the children of American adolescent mothers, the rate is
over 31% (Broussard 1995).
Disorganized attachment is also
relatively common among the Dogon of Mali (~25%, True et al 2001),
infants living on the outskirts of Cape Town, South Africa (~26%,
Tomlinson et al 2005) and undernourished children in Chile (Waters and
Why local populations differ
In some cases, these outcomes may reflect differences in the way
infants perceive the Strange Situation, rather than real differences in
For instance, Israeli children raised in kibbutzim
rarely meet strangers. As a result, their high rates of resistant
behavior during the Strange Situation test may have had more to do with
heightened fear than with the nature of their maternal bonds (Sagi et al
Similarly, the Japanese results were probably skewed by
the facts that Japanese infants are virtually never separated from their
mothers (Miyake et al 1995). Nor do Japanese people value independence
and independent exploration to the same degree that Westerners do, with
the result that otherwise securely-attached babies may explore less
(Rothbaum et al 2000).
But in other cases, results of the Strange
Situation may reveal genuine cultural differences in the way that
children have attached to their mothers. For example, researchers
analyzing a variety of attachment studies concluded that German and
American infants perceived the Strange Situation in similar ways (Sagi
et al 1991). So the relatively high incidence of avoidant-insecure
attachments in Germany may reflect real differences in the way that some
Germans approach parenting.
Has attachment research overemphasized the mother-infant bond? Some evolutionary considerations.
One criticism of the Strange Situation procedure is that it has focused almost exclusively on the mother-infant bond.
part, this may reflect a cultural bias. Many people who study
attachment come from industrialized societies where mothers usually bear
most of the responsibility for childcare.
But in some families, fathers spend a great deal of time with their children.
in some parts of the world, grandmothers, aunts, uncles, and siblings
make substantial--even crucial--contributions to childcare.
fact, among some modern-day foragers, like the Aka and Efe of central
Africa, infants spend the much of the day being held by someone other
than their mothers (Hewlett 1991; Konner 2005).
Such evidence has
inspired evolutionary anthropologists to “rethink...assumptions about
the exclusivity of the mother-infant relationship" (Hrdy 2005).
instance, anthropologist Sarah Blaffer Hrdy has argued that
non-maternal caregivers may have played an important role in human
evolution (Hrdy 2005). When infants have multiple caregivers, their
mothers bear less of the cost of child-rearing. Mothers can afford to have
more children, and their children can afford to grow up more slowly.
these life-history traits—higher fertility and an extended
childhood—distinguish humans from our closest living relatives, the
great apes (Smuts et al 1989). And ape mothers—unlike many human
mothers—must raise their kids without helpers.
“allocare" (non-maternal childcare) gave our ancestors the edge—allowing
us to reproduce at faster rates than our nonhuman cousins.
If so, it seems doubtful that human babies are “designed" for exclusive attachments to a single, maternal caregiver.
this point doesn’t detract from the importance of Strange Situation
studies, it reminds us that infants can bond with more than one person.
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