Do individual differences in attachment matter? Ainsworth argues that secure attachment in the first year of life provides an important foundation for psychological development later in life. The securely attached infant moves freely away from the mother but keeps track of where picked up by others, and when put back down, freely moves away to play. An insecurely attached infant, by contrast, avoids the mother or is ambivalent toward her, fears strangers, and is upset by minor, everyday separations.
If early attachment to a caregiver is important, it should be linked to a child’s social behavior later in development. For some children, early attachments seem to foreshadow later functioning (Bretherton, 2012; Brisch, 2012; Kok & others, 2012). Consider the following studies:
• In the extensive longitudinal study conducted by Alan Sroufe and his colleagues (2005), early secure attachment (assessed by the Strange Situation at 12 and 18 months) was linked with positive emotional health, high self-esteem, self-confidence, and socially competent interaction with peers, teachers, camp counselors, and romantic partners through adolescence.
• Being classified as insecure resistant in infancy was a negative predictor of cognitive development in elementary school (O’Connor & McCartney, 2007).
• Yet another study found that attachment security at 24 and 36 months was linked to the child’s enhanced social problem-solving skills at 54 months (Raikes & Thompson, 2009).
An important issue regarding attachment is whether infancy is a critical or sensitive period for development. The three studies just described show continuity, with secure attachment in infancy predicting subsequent positive development in childhood and adolescence. For some children, though, there is little continuity. Not all research reveals the power of infant attachment to predict subsequent development (Roisman & Groh, 2011; Th ompson, 2013a). In one longitudinal study, attachment classification in infancy did not predict attachment classification at 18 years of age (Lewis, Feiring, & Rosenthal, 2000). In this study, the best predictor of an insecure attachment classification at 18 was the occurrence of parental divorce in the intervening years. Consistently positive caregiving over a number of years is likely an important factor in connecting early attachment with the child’s functioning later in development. Indeed, researchers have found that early secure attachment and subsequent experiences, especially maternal care and life stresses, are linked with children’s later behavior and adjustment (Th ompson, 2013a). For example, a longitudinal study revealed that changes in attachment security/insecurity from infancy to adulthood were linked to stresses and supports in socioemotional contexts (Van Ryzin, Carlson, & Sroufe, 2011). These results suggest that attachment continuity may be a reflection of stable social contexts as much as early working models. The study just described (Van Ryzin, Carlson, & Sroufe, 2011) reflects an increasingly accepted view of the development of attachment and its influence on development. That is, it is important to recognize that attachment security in infancy does not always by itself produce long-term positive outcomes, but rather is linked to later outcomes through connections with the way children and adolescents subsequently experience various social contexts as they develop.
The Van Ryzin, Carlson, and Sroufe (2011) study reflects a developmental cascade model, which involves connections across domains over time that influence developmental pathways and outcomes (Cicchetti, 2013; Masten, 2013). Developmental cascades can include connections between a wide range of biological, cognitive, and socioemotional processes (attachment, for example), and also can involve social contexts such as families, peers, schools, and culture. Further, links can produce positive or negative outcomes at different points in development, such as infancy, early childhood, middle and late childhood, adolescence, and adulthood.
In addition to challenging whether secure attachment in infancy serves as a critical or sensitive period, some developmentalists argue that the secure attachment concept does not adequately consider certain biological factors in development, such as genes and temperament. For example, Jerome Kagan (1987, 2002) points out that infants are highly resilient and adaptive; he argues that they are evolutionarily equipped to stay on a positive developmental course, even in the face of wide variations in parenting. Kagan and others stress that genetic characteristics and temperament play more important roles in a child’s social competence than the attachment theorists, such as Bowlby and Ainsworth, are willing to acknowledge (Bakermans-Kranenburg & van IJzendoorn, 2011). For example, if some infants inherit a low tolerance for stress, this, rather than an insecure attachment bond, may be responsible for an inability to get along with peers. One study found links between disorganized attachment in infancy, a specific gene, and levels of maternal responsiveness (Spangler & others, 2009). In this study, infants with the short version of the gene—serotonin transporter gene, 5-HTTLPR—developed a disorganized attachment style only when mothers were slow in responding to them.
A third criticism of attachment theory (in addition to the critical/sensitive period issue and inadequate attention to biological-based factors) is that it ignores the diversity of socializing agents and contexts that exists in an infant’s world. A culture’s value system can influence the nature of attachment. In some cultures, infants show attachments to many people. Among the Hausa (who live in Nigeria), both grandmothers and siblings provide a significant amount of care for infants (Harkness & Super, 1995). Infants in agricultural societies tend to form attachments to older siblings, who are assigned a major responsibility for younger siblings’ care. Researchers recognize the importance of competent, nurturant caregivers in an infant’s development (Grusec, 2011b; Roisman & Groh, 2011); at issue, though, is whether or not secure attachment, especially to a single caregiver, is critical (Lamb, 2010; Thompson, 2013a).
Despite such criticisms, there is ample evidence that secure attachment is important in development (Thompson, 2013a; Sroufe, Coffino, & Carlson, 2010). Is secure attachment the sole predictor of positive developmental outcomes for infants? No, and neither is any other single factor, but secure attachment in infancy is important because it reflects a positive parentinfant relationship and provides the foundation that supports healthy socioemotional development in the years that follow.