Psychologist Mary Ainsworth devised the Strange Situation procedure to test the quality of an infant's attachment to his mother. This article
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
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 experimental room.
The room has toys or other interesting things in it, and the mother lets the child explore the room on her own.
After 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:
Avoidantly-attached 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; Valentin 2005).
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.
Studies 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).
However, 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).
Studies 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 Valenzuela 1999).
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 attachment.
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 1991).
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.
In 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.
And in some parts of the world, grandmothers, aunts, uncles, and siblings make substantial--even crucial--contributions to childcare.
In 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).
For 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.
Interestingly, 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.
So perhaps “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.
While 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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