How does attachment occur? What psychological forces drive and regulate the formation of this emotional bond with caretakers? Over the years, several mechanisms have been proposed:
- Instinct. It has been argued that attachment is essentially a highly adaptive instinct
[(Bowlby, 1969). In this view, helpless human infants would not survive without the care and protection of an adult, and so the emotional bond between baby and parent would provide a great advantage in the struggle for survival. Advocates of this theory propose that infants are biologically driven to target adults for attachment, and that cries and smiles from the infant instinctively elicit comfort and attention from mothers] [ (Sigelman & Shaffer, 1995). Based primarily on observations of animals ] [(e.g., Lorenz, 1937), other researchers have suggested there is a
shortly after birth when attachment naturally and inevitably occurs. Recently hatched geese or ducks, for example, will automatically form strong attachments to any large, moving object in their immediate vicinity within hours ] [(Johnson, 1992). Although some theorists have proposed a similarly short "window of opportunity" for attachment in human infants, most developmental psychologists believe that our attachment to caregiving adults develops more gradually ] [(Eyer, 1992).
- Reinforcement. From birth, infants depend on their caregivers for nourishment and relief from discomfort as well as stimulation, play, and information about the world. This makes the parent the primary source of
for the baby, a "supermarket" from which most rewards can be obtained. Learning theorists have suggested, therefore, that the principles of
are sufficient to explain the tendency for infants to seek out and affiliate with parents. Feeding alone, it has been argued, would be a powerful enough reinforcer to promote the development of attachment behaviors in the infant.
- Contact comfort. In a series of classic experiments, Harry Harlow and his colleagues at the University of Wisconsin challenged the "supermarket" or feeding theory of attachment
[(Harlow & Zimmerman, 1959; Harlow et al., 1971). In these studies, newborn rhesus monkeys were separated from mothers soon after birth and raised in isolation. Harlow had noticed that these infant monkeys became extraordinarily attached to the soft blankets lining their cages, holding on to them tightly and becoming distressed when the blankets were removed for cleaning. Harlow hypothesized that comfortable physical contact was the critical factor in the formation of attachment. In one experiment, Harlow provided the young rhesus monkeys with two different types of "surrogate" artificial mothers. One artificial mother was constructed of bare metal wire but included an artificial nipple for feeding; another model had no nipple but was constructed of foam rubber padding covered in soft fabric. It became clear that the infant monkeys were more strongly attached to the "comfortable" surrogate mother, clinging to it in preference to the wire model that provided food. When frightened, they would run to the padded "mother," and they were distressed when separated from it. Obviously, Harlow used rhesus monkeys because no controlled experiments on maternal deprivation could be conducted with human infants, but many researchers feel that contact comfort is important in human attachment as well.
- Sensitive responding. Many theorists assume that secure attachment can only develop when the parent consistently and reliably responds to the needs of the child. An erratic or unresponsive parent is presumed to promote insecure attachment
[(DeWolff & van Ijzendoorn, 1997; Lamb, Thompson, Gardner, Charnov, & Estes, 1984).To be a responsive caregiver, the parent must be sensitive to signs of pleasure or distress from the infant. For example, Bell & Ainsworth ] [(1972) found if parents responded quickly to a crying infant in the first 3 months, those infants began crying less often over the next 4 months. Ainsworth ] [(1979) described the parents of insecure children (especially those with avoidant attachment styles) as often impatient and inconsistent in their responsiveness to the child's needs.
- Temperament. Infants are not neutral in the attachment process. The character or temperament of the infants themselves may make a difference in the nature of the eventual attachment. Almost from birth, babies react to the world with relatively consistent patterns of emotion, activity, and sociability; these patterns are referred to as
[ (Buss & Plomin, 1984). For example, roughly 10% of infants can be categorized as "difficult"; that is, they are consistently more irritable, moody, and less tolerant of changes to their routines ] [(Thomas & Chess, 1977). Difficult, fussy babies are somewhat less likely to be securely attached to caregivers ] [(Seifer et al., 1996). This is especially true when the mother is rigid or inflexible and unable to cope well with a more demanding child ] [(Mangelsdorf et al., 1990).