Results of these prospective longitudinal analyses support earlier evidence from the Ogawa et al. (1997)
longitudinal study that the quality of the early caregiving relationship is an important contributor to the development of dissociation. Objectively assessed quality of early care in the first 18 months of life accounted for approximately half of the variability in young adult dissociative symptoms assessed 20 years later, a surprisingly large portion of the variance over such a long time-span. Ogawa et al. (1997)
also found that quality of the parent-infant relationship accounted for one-quarter of the variance in young adult dissociative symptoms. The combined sample size of the two studies represents over 180 young adults, lending considerable support to these findings.
In addition, the specific type of impairment in the early parent-infant relationship related to later dissociation was congruent across studies despite differences in methodology. In the current study, mother’s lack of positive affective involvement and flatness of affect at home, as well as her disrupted affective communication in the lab, were the important precursors to later dissociative symptoms. Hostile-intrusive forms of interaction at home were also evaluated as predictors of dissociation, but did not account for significant variance, despite their association with early maltreatment and later externalizing behavior problems in the same sample (Lyons-Ruth, Easterbrooks & Cibelli. 1997
). In the Ogawa et al. (1997)
study, a broad clinical composite judgment of the mother’s psychological unavailability to the infant (Egeland & Sroufe. 1981
) was the single most important predictor of age 19 dissociative symptoms. Therefore, there was considerable specificity to the aspects of parental interaction associated with the development of dissociation. These results suggest that the DES is indexing unintegrated mental states that develop not only in response to trauma, but also as a response to the effects of parental emotional unavailability beginning in the first years of life.
Based on previous research, we expected childhood abuse to add to the prediction of dissociation. To strengthen the assessment of abuse as much as possible, three separate assessments were used involving multiple methodologies. Similar to the Ogawa et al. (1997)
findings, however, abuse did not predict DES scores regardless of the assessment method used. We considered several potential explanations for these findings.
First, it is possible that our sample may have underreported their childhood abuse experiences since two of the three measures employed to assess childhood trauma were based on self-report or interview measures. While this possibility cannot be ruled out, 18% of participants had maltreatment charges substantiated by the state, such that self-report was not relied on for those cases. Such early state-documented maltreatment did not predict later dissociation, however.
Second, the lack of relation between childhood trauma and dissociation may be due to the low levels of pathological dissociation endorsed by our sample. One participant was categorized as a DES-T taxon member and only 7% of the sample scored 30 or higher on the DES, an empirically identified cut-off score for assessing pathological dissociation with the DES (Leavitt, 1999
). Furthermore, the sample’s mean DES score was 16.29, which is only slightly higher than the average (14.4) reported by van IJzendoorn and Schuengel’s (1996)
for adolescents and students. As the majority of our participants did not endorse pathological levels of dissociation on the DES, it is possible that a stronger association between dissociation and trauma exists in samples endorsing a higher severity and/or frequency of dissociative experiences. However, 11% (n = 18) of Ogawa et al.’s (1997)
sample was identified as DES-T taxon members, and their findings also demonstrated that psychological unavailability of caregiver and disorganized infant attachment significantly predicted DES-T taxon membership, while childhood trauma did not.
A third explanation for the lack of association between childhood trauma and dissociation in these studies is that only certain forms of extremely severe and/or chronic abuse are associated with dissociation, and that these are more likely to occur in patient samples. Relevant to this point is that trauma has been implicated as an etiological factor in a variety of other psychiatric disorders. Therefore, we need an account of why some people develop dissociation in the context of trauma, while others develop other disorders or no disorder at all. This may be related to the type of the trauma experienced and/or to the particular characteristics of the ongoing family relationships within which the trauma occurs. The specific contexts and characteristics of abuse associated with dissociation as opposed to other psychopathological outcomes deserve further study.
The final possibility is that dissociation may develop as the result of family relational factors other than physical or sexual abuse, as supported by both the present results and the results of the Ogawa et al. (1997)
study. Notably, the only type of childhood trauma that did add to the prediction of dissociative symptoms in the current study was severity of verbal abuse, which was not a variable assessed in the Ogawa et al. (1997)
study. Verbal abuse has shown a robust relation to DES scores in other work as well. Teicher et al. (2006)
, for example, found the relationship between verbal abuse and DES scores to be comparable and/or stronger than that of other types of abuse, including sexual and physical abuse, as well as domestic violence. Their findings also demonstrated that, after controlling for the effects of physical and sexual abuse, the combined
effect of verbal abuse and witnessing domestic violence (which they defined as “emotional abuse”) was significantly larger than the effects for physical and sexual abuse. They suggest that verbal abuse may cause a child to have a “negative model for interpersonal communication,” which s/he in turn employs in future relationships, and that this model might be preceded by poor early attachment experiences and result in negative internalized representations of the self, particularly in relation to others.
These findings indicate that young adults who have experienced lack of parental affective involvement in infancy, as well as further verbal or emotional abuse in childhood, may be at particularly elevated risk for dissociation. It is notable that both of these experiences may index moment-to-moment, and possibly chronic, impairments in the process of parent-child communication, rather than more discrete traumatic events. In particular, the early lack of a caregiver to whom one can communicate one’s distress and discomfort and elicit a soothing response appears to heighten the risk for dissociation later in life.
Why might quality of early care show such a strong relation to lack of mental integration 19 years later? While there may be a number of intervening processes carrying this correlation over time, here we highlight two potential mechanisms of continuity suggested by these data and consistent with other studies in the infancy literature.
We propose that dissociation is not a purely intrapsychic phenomenon but instead is a way of organizing thought and attentional processes in response to implicit social injunctions from primary attachment figures “not to know.” While we know from patient report that such social injunctions at times take the form of explicit threats of harm or abandonment, more often such injunctions about what can be included in a dialogue with others, especially very early in development, are communicated implicitly rather than explicitly, through the caregiver’s differential responsiveness to different kinds of child communications. That is, the kinds of feelings and experiences the child can bring into interactions with the parent are shaped implicitly from the beginning of life in the parent’s responses or non-responses to the infant’s uncomfortable, distressed, or frightened reactions, as well as to the infant’s positive bids for pleasurable interactions. Therefore, such shaping of what can be included in the dialogue takes place in the intense affective field of the early attachment relationship. From this perspective, defensive processes such as dissociation can be viewed as socially constructed ways of relating, rather than as primarily intrapsychically-generated responses to traumatic events. This is not an affectively bland social constructive process, however, but a way of mentally accommodating to intense social pressures not to acknowledge pain and distress within a set of caregiving relationships that are vital for survival. The attachment relational context imbues both the caregiving transactions and their internalized mental representations with the intense emotional valences characteristic of defensive responses. This valence does not come simply from an intrapsychic need not to know, but also from a relational communication not to speak. Such implicit injunctions are powerfully conveyed in the videotaped database of the study.
This emphasis on the importance of the two-person interaction in generating dissociative tendencies shifts the emphasis somewhat from Liotti’s hypothesis that the child’s early disorganization of attachment strategies sets up an early intrapsychic vulnerability to dissociation. Instead, the accumulated longitudinal findings now point to the early (and potentially continued) non-responsiveness of the interaction between parent and child as the more powerful predictive factor over time, with infant attachment disorganization as a possible, but not necessary, concomitant of the disturbed parent-child relationship. Therefore, the hypothesis that emerges is that a parent-child affective dialogue that repeatedly signals the parent’s reluctance or refusal to respond to infant fear or distress shapes the child’s corresponding mental organization. The result of this may be that a part of the child’s mind corresponding to the parental stance cannot be responsive to or aware of another part of the child’s mind that contains the distressed and frightened experience. Because dissociation is a rare outcome, however, we would expect that the caregiving deviations associated with this disorder would need to be both extreme and sustained over time.
Second, based on attachment theory and research, the long-term impact of parental affective unresponsiveness can also be viewed from a psychobiological viewpoint. In infancy the child is unusually dependent upon the parent’s responsive involvement for regulation of stressful arousal from a variety of sources. Experimental animal models have repeatedly confirmed the role of the quality of early care in setting enduring parameters of the stress response system in the HPA axis (e.g. Coplan et al., 1996
; Francis et al., 1999
). In human studies as well, infant cortisol responses after brief stressors have also been shown to relate to the security of attachment to the caregiver accompanying the infant at the time of the stressor (Hertsgaard et al., 1995
; Spangler & Grossmann, 1993
). Therefore, parental affective unresponsiveness can be conceptualized from a psychobiological viewpoint as a form of ‘hidden trauma’ specific to infancy - trauma that has the potential to hyperactivate the infant’s responses to stressors over time. Such heightened vulnerability to stressors, in combination with an implicit injunction from very early in life not to bring one’s fear and distress to the caregiver for comfort and soothing, may then shape the ‘choice’ of dissociation as one of the few available means for achieving a modicum of relief from fearful arousal.
With both biological stress regulation and integrative dialogue with a responsive developmental partner fundamentally impaired from early in life, we would expect a cascade of further developmental consequences to accrue over time that have implications for reactions to threat, coping mechanisms when under stress, and the continuing integration of thought.
The first limitation of the present study is its modest sample size, leading us to limit our statistical models to variables with a strong grounding in previous literature. Secondly, assessing the presence of abuse from participant report has well-known limitations regarding potential reluctance to disclose, particularly among non-patient samples. While this is mitigated here by prospective data collection on state protective services involvement, we cannot rule out that the relative lack of prediction from abuse experiences may reflect the presence of undetected or unreported abuse.
Third, participants did not demonstrate the clinically significant levels of dissociation consistent with dissociative disorders or DES-T taxon membership. Abuse experiences may be more strongly associated with dissociation in samples with more pathological levels of dissociation. Therefore, these data do not rule out the possibility that childhood experiences of abuse are particularly influential in the development of more severe forms of dissociation. These findings do indicate, however, that caregiver emotional availability may play a more significant role in the genesis of dissociation than previously thought and should be further evaluated in clinical cohorts as an additional factor supporting the emergence of dissociation.