The latest issue of Current Directions in Psychological Science contains an interesting article on early infant-mother attachment, by Myron Hofer. His work is based on research with rats, but nevertheless, there is much interesting data that is relevant to humans.
The term, attachment, as Hofer uses it, refers to “the processes that maintain and regulate sustained social relationships” (p. 84). Attachment between mother and infant is the first bond that occurs. Much clinical and social experience over the last 50 years has shown that inhibiting this process has long and severe consequences for the infant. The current thinking is that both reactive attachment disorder and antisocial personality disorder stem from impaired attachments during infancy and childhood. There are also suggestions that borderline personality disorder is also related to disrupted attachment.
Hofer addresses three issues. First, he presents data suggesting the attachment bond is created through the interaction of mother and infant through a complex pairing of stimuli. Apparently, there is an early period, immediately after birth, when the infant rapidly learns to associate smells, sounds, taste, and touch with the mother. It happens quite rapidly, enabling the infant to discriminate the mother from other parents and probably from other objects in the infant's environment.
Interestingly, Hofer mentions some data that indicates that aversive stimulation may intensify the bonding. He links this finding with the intense bond between a child and an abusive parent, and why this occurs needs to be clarified. Rapid bonding between the infant and the mother makes good sense from an evolutionary point of view. The mother provides all of the infants needs for survival, so the sooner the infant can recognize the mother the better. But the reason for increased attachment in the face of pain makes no sense to me.
The second issue involves the question of why maternal separation is stressful. Hofer says that basic biological processes are initially regulated by the mother in subtle ways. In describing an experiment with rats, he commented, “We concluded from these surprising results that warmth provided by the mother normally maintained the pup's activity level and that her milk maintained her pup's heart rate. Maternal separation withdrew these regulatory influences that were hidden within the ordinary mother–infant interactions, resulting in slowed behavior and low heart rate.” (p. 86).
The final issue Hofer addresses is why disruption of the early maternal-infant relationship can have lasting effects. Hofer argues, “when all maternal regulators are withdrawn early, a number of physiological and behavioral systems are altered in their developmental paths and in their relation to each other, creating a complex, changing pattern of vulnerability over the life span.” (p. 86). Interestingly, not all those changes are negative, which is consistent with what humans will tell you.
People who have gone through arduous childhood experiences often comment that they take away some positives from it. For example, some of my clients have said that because of the abuse they suffered as child, they have learned to manage stress better than their friends. They do not minimize the experience or deny how bad it was. They simply recognize that they did manage to take something positive from it.
Finally, it's always a pleasure to read a basic science article that has implications for practice. There's an awful lot of stuff out there that will never be of any real use to anyone beyond a line on a vita.
Hofer, Myron A. (2006). Psychobiological Roots of Early Attachment. Current Directions in Psychological Science 15 (2), 84-88. doi: 10.1111/j.0963-7214.2006.00412.x