An emotional bond between an infant or animal and its caregiver, contributing to the infant or animal's experience of safety, comfort, and security while in the caregiver's presence and distress when temporarily separated.
Many developmental psychologists view attachment—the special relationship between infant and care-giver—as an important building block for later relationships and adult personality. Since attachment plays a central role in theories of social and emotional development, the scientific study of attachment has remained in the forefront of developmental psychology for the past several decades.
John Bowlby, a psychoanalytically trained clinician, developed modern attachment theory in the 1950s as a variant of object-relations, which was a variant of Freud's theory that the infant's tie to the mother is the cornerstone of adult personality.
Bowlby integrated a number of approaches into his theory, including systems and evolutionary theories to formulate a modern attachment theory.
Before widespread acceptance of Bowlby's theory, psychologists viewed attachment as a secondary drive, derived from primary drives like hunger. It was thought that attachment to the mother occurred because she supplied food and became the object of the infant's attachment through association with feeding and the reduction of other primary needs. Prior to Bowlby's theory, behaviorist psychologists theorized that the need for attachment arose from an infant's physical needs for food and warmth, both of which were provided by the mother. They believed that a baby's preference for the mother was the result of conditioning. A child was thought to be overly attached if crying and clingy behavior occurred frequently.
Research in the 1950s, however, cast these theories into doubt. One of the most famous research studies in this area was performed by Harry Harlow. He placed infant monkeys in a cage with two surrogate mother dolls: one made of wire holding a bottle of milk and the other made of soft cloth. According to the behaviorist view, the monkey should have developed an attachment to the wire mother because she was the source of food. But the infant monkeys developed attachments to the cloth mothers, suggesting that the need for comfort and warmth are more important, or more psychologically ingrained, than the need for food.
Later experiments with monkeys also revealed the effects secure attachments had on infants. In one experiment, strange foreign objects were introduced to a cage with an infant monkey. When alone, the monkey would react with fear. When the cloth mother was present, however, the infant would first retreat to the mother in fear, but then, having been reassured, it would begin to explore the foreign object. Human infants, too, are much more likely to react with fear to unknowns if a mother is not in the vicinity. With a mother present, however, an infant is much more exploratory—even if the mother is not within sight but nearby.
Bowlby became one of the first to map out stages of attachment, addressed in his writings, including his 1980 book, Attachment and Loss. Bowlby suggested that from birth until about the age of three months, babies are in the initial pre-attachment phase. Here, infants simply need to be held and demonstrate no preference for who does the holding. The next phase, attachment-in-the making phase, takes place from three to four months and is marked by an infant's emerging preference to be held by familiar figures, although it is important to note that the figure does not necessarily have to be the mother. According to Bowlby, the final stage of attachment is the clear-cut attachment phase. Beginning at about six months, this phase features an infant's clear insistence on its mother or its primary caregiver.
Mary Ainsworth, a prominent researcher in attachment and an associate of Bowlby's, devised a test to measure the type and degree of attachment a child feels for his mother. The test, called the Ainsworth Strange Situation test, involves a mother leading her child into a strange room, which the child is free to explore with the mother present. A stranger then enters the room and the mother leaves. If the infant becomes distressed, the stranger will try and console her. The mother then returns and the stranger leaves. In another scenario, the mother leaves again after the stranger returns. Finally, the mother returns for good and the stranger leaves. Based on the infants' response to their mothers' return, children are labeled "securely attached," "avoidant," or "ambivalent."
Psychologists believe that attachment serves to help children begin exploring the world. As the above studies show, if presented with a strange situation, an infant will either avoid or engage in exploration, chiefly dependent upon whether an attachment figure is present. Additionally, it has been shown that lack of attachment in early life can have a negative impact on exploratory propensity in later life. In 1971, researchers separated a group of monkeys from their mothers for six days and then analyzed their behaviors two years later in comparison to a control group that had not undergone separation. The group that had been separated was observed to be far more reticent in exploratory behaviors than the control group. Still other studies indicate that cognitive functioning in children is enhanced among "securely attached" (according to the Ainsworth scale) infants.
Karen, Robert. Becoming Attached: Unfolding the Mysteries of the Infant-Mother Bond and Its Impact on Later Life. New York: Warner Books., 1994.
Thompson, Andrea. "The Affection Factor." Working Mother (April 1995): 63.
Wise, Nicole. "What's in Passion?" Parenting (May 1993): 131.