Bowlby viewed development in terms of pathways, wherein change is always possible, but is constrained by paths previously taken. This model provides a fundamentally new way of looking at psychopathology—not as conditions some people simply have, but as complex outcomes of the succession of adaptations they've made. Anxious attachment doesn't directly cause later disturbance, but it initiates a developmental pathway that, without corrective experiences, increases the probability of psychopathology. In fact, anxious/resistant attachment increases the probability of anxiety disorders and avoidant attachment increases the likelihood of conduct problems. Moreover, the strongest predictor of pathological outcomes, including dissociation, is "disorganized attachment," a pattern discovered by the noted attachment researcher Mary Main.
Disorganized attachment results when frightening or abusive parental behavior places infants in an irresolvable conflict: the desire to move toward the caregiver and flee from the source of fear, when they're one and the same person. This activates two brain circuits simultaneously. The attachment circuitry screams out: "Go to my attachment figure for protection!" Yet, at the same time, an even older circuit of survival screams, "Get away from this source of terror!" The same person triggers approach and avoidance, and the infant's capacity for an organized response collapses. This relational experience predicts the disorganized pattern of attachment in several studies. Further, this "disorganized" infant attachment pattern predicts later dissociative symptoms up to age 26 (and even borderline personality symptoms at age 28).
How Development Works
Recent research on the interactions among genes, social environmental factors, and history has shown how obsolete the old nature vs. nurture distinction has become. One example is the work of biological psychologist Stephen Suomi, who's been working with monkeys in highly controlled experiments. These studies have shown that two genetic variations that have been associated with alcohol abuse or impulsiveness in humans are linked to totally different outcomes when the infant monkeys are reared by a group of highly nurturing foster mothers rather than by their birth mothers. These genetic-variant animals raised by nurturing mothers, in fact, are less likely to abuse alcohol than other monkeys and likelier to be peer group leaders.
Scientists such as Suomi and Michael Meaney of McGill University are now working out how experience influences gene expression. Meaney has shown, for example, that the quality of early relational experience—in rats, and in people—influences the regulatory molecules that control gene expression in areas of the brain that determine stress responses. Recent studies in humans have found that more disabling impacts of trauma as a likelier outcome of frightening attachment histories when certain genetic variants are present, coupled with specific epigenetic changes in the regulation of gene expression.
It's important to remember that, according to John Bowlby and the proponents of attachment theory, every starting point, however early one looks, is also an outcome; every outcome is also a starting point. Researchers Michael Mackenzie and Susan McDonough, for example, found that variations in crying at 15 months predicted both measures of temperament and behavior problems at 24 months. Simple conclusions must be avoided, however, because crying at 7 months didn't predict crying at 15 months, or later behavior problems. Nevertheless, the degree to which mothers were bothered by the infants' crying at 7 months (which wasn't related to the actual amount of crying) predicted both later crying and behavior problems. Moreover, the 7-month measures were predicted by parent–child relationship representations produced by parents during the newborn period. Thus, the match between parental expectations and the characteristics of the infant is a powerful determinant of developmental outcome, as Stella Chess and Alexander Thomas suggested in their studies of temperament decades ago.