Dr M.J. Bakermans-Kranenburg
Department of Education and Child Studies, Leiden University
Wassenaarseweg 52, P.O.Box 9555, 2300 RB Leiden, The Netherlands
Tel. *-31-71-5273798/5273434 (secr.); fax *-31-71-5273945 k 3B35
E-mail: bakermans
MA degree (Date: March 1989): Leiden University, Center for Child & Family Studies
Main subject: Attachment and maternal structuring
PhD degree (Date: 07-10-1993): Leiden University, Faculty of Social and Behavioural Sciences; Supervisor (‘Promotor’): Prof.dr. M.H. van IJzendoorn
Title of thesis: Het Gehechtheidsbiografisch Interview (The Adult Attachment Interview: Psychometric analyses)
Assistant Professor 1993-1995, Centre for Child & Family Studies
Associate Professor 1995- present, Centre for Child & Family Studies
van Ijzendoorn MH, Schuengel C, Bakermans-Kranenburg M.J.(1999) Disorganized attachment in early childhood: Meta-analysis of precursors, concomitants, and sequelae. Development and Psychopathology, 11(2): 225-249
Willemsen-Swinkels, S., Bakermans-Kranenburg, M.J., Buitelaar, J.K., Van IJzendoorn, M.H., Van Engeland, H. (2000). Insecure and disorganized attachment in children with a Pervasive Developmental Disorder: Relationship with social interaction and heart rate. Journal of Child Psychiatry and Psychology, 41, 759-767.
This study on children with a Pervasive Developmental Disorder (PDD; N = 32), children with developmental language disorder (N = 22), and normally developing children (N = 28) sought to answer questions concerning attachment and autistic behaviour. We could replicate the finding that children with a PDD are able to develop secure attachment relationships to their primary caregiver. Children with PDD who had an insecure attachment showed fewer social initiatives and responses than children with PDD who had a secure attachment, even when the insecurely and securely attached PDD children were matched on chronological and mental age. Children with both a PDD and mental retardation were more often classified as disorganised.Three findings suggested that a disorganised attachment does not merely reflect the presence of "autistic" behaviour: (1) children with PDD did not reveal higher rates of a disorganised attachment than matched comparison children; (2) having a PDD diagnosis and having a disorganised attachment were found to be associated with opposite effects on an ethological measure of level of behavioural organisation; and (3) a disorganised attachment but not a PDD diagnosis was associated with an increase in heart rate during parting with the caregiver and a decrease in heart rate during reunion.
Van IJzendoorn, M.H., Moran, G., Belsky, J., Pederson, D., Bakermans-Kranenburg, M.J., & Kneppers, K. (2000). The similarity of siblings’ attachments to their mother. Child Development, 71, 1084-1096.
Do siblings develop similar attachment relationships with their mother? Attachment theory suggests that brothers and sisters growing up in the same family are likely to relate in similar ways to their parents, at least when parental attachment representations and interactive styles remain stable across time. In the current study, sibling attachment data from three research groups (from Pennsylvania State University, Leiden University, and the University of Western Ontario) have been pooled to assemble a sufficiently large sample of observations (N = 138 sibling pairs) for a detailed comparison of sibling attachment relationships. Spacing between the births, differences in maternal sensitivity, and gender of siblings were examined as possible sources of concordance of nonconcordance. Attachment security (including disorganized attachment) of each sibling was assessed with the Strange Situation procedure between 12 and 14 months after birth. Maternal sensitivity was observed with the same rating scale in a laboratory play session in one of the studies and in home observations in the others. Sibling relationships were found to be significantly concordant when classified as secure/nonsecure (62% concordance, p < .01, 1-tailed, intraclass correlation = .23) but not when further subcategorized. Maternal insensitivity to both siblings (shared environment) was associated with concordance of sibling nonsecurity. Siblings of the same gender were more likely to form concordant relationships with their mother (68%; p < .01, 1-tailed, intraclass correlation = .37) than those of opposite gender. Same-sex sibling concordance was comparable to the concordance found for monozygotic twins in earlier studies. Genetic factors may, therefore, play a relatively small role in the development of attachment.
Van der Mark, I., Bakermans-Kranenburg, M. J., & Van IJzendoorn, M.H. (2002). The role of parenting, attachment, and temperamental fearfulness in the prediction of compliance in toddler girls. British Journal of Developmental Psychology, 20, 361-378.
The development, antecedents, and concomitants of committed compliance in the second year of life were investigated, with a special emphasis on the influences of parental discipline and sensitivity, attachment security, and temperamental fearfulness. At 16 and at 22 months, 125 first-born girls from middle-class families were observed in their homes and in the laboratory. Committed compliance was assessed in a clean-up task ('do' task), and in a task in which the children were asked to refrain from touching attractive toys ('don't' task). Temperamental fearfulness was observed when the children were confronted with seven somewhat scary items, such as a stethoscope and a rubber bird of prey. Attachment security was assessed with the Strange Situation procedure, and parental discipline and sensitivity measures were derived from home and lab observations in problem-solving and limit-setting situations. Maternal sensitivity during a puzzle task was related to more compliance of the child to her prohibitions, and maternal intrusiveness was associated with less compliance to maternal requests. Committed compliance was associated with concurrent parenting, attachment, and temperament. Controlling for concurrent parenting, attachment, and temperament, we did not find any significant associations between antecedent parenting and later compliance. Our data failed to support Kochanska's (1995, 1997) model of the impact of antecedent socialization and temperament on emergent morality.
Van der Mark, I.L., Van IJzendoorn, M.H., & Bakermans-Kranenburg, M.J. (2002). Development of Empathy in girls during the second year of life: Associations with parenting, attachment, and temperament. Social Development, 451-468.
The development, antecedents, and concomitants of empathic concern in the second year of life were examined. Associations with parental sensitivity, children's fearfulness and attachment security were investigated. At 16 and at 22 months, 125 firstborn girls from middle-class families were observed in their homes and in the laboratory. Empathic concern was assessed from the girls' responses to simulated distress in their mothers and in an unfamiliar person. Temperamental fearfulness was observed when they were confronted with potentially scary items. Attachment security was assessed with the Strange Situation procedure, and parental sensitivity was measured in problem-solving situations both at home and in the lab. From 16 to 22 months, empathic concern,for the mother's distress increased, whereas empathy for the stranger decreased. A more fearful temperament and less attachment security predicted less empathic concern for the stranger's distress. Antecedent and concurrent measures of parenting showed disappointingly weak associations with empathic concern. Empathy for strangers in distress requires the regulation of negative emotions for which fearful and insecurely attached girls seem to be less well equipped.
Bakermans-Kranenburg, M.J., Van IJzendoorn, M.H., & Juffer, F. (2003). Less is more: Meta-analyses of sensitivity and attachment interventions in early childhood. Psychological Bulletin, 129, 195-215.
Is early preventive intervention effective in enhancing parental sensitivity and infant attachment security, and if so, what type of intervention is most successful? Seventy studies were traced, producing 88 intervention effects on sensitivity (n = 7,636) and/or attachment (n = 1,503). Randomized interventions appeared rather effective in changing insensitive parenting (d = 0.33) and infant attachment insecurity (d = 0.20). The most effective interventions used a moderate number of sessions and a clear-cut behavioral focus in families with, as well as without, multiple problems. Interventions that were more effective in enhancing parental sensitivity were also more effective in enhancing attachment security, which supports the notion of a causal role of sensitivity in shaping attachment.
Bokhorst, C.L., Bakermans-Kranenburg, M.J., Fearon, P., Van IJzendoorn, M.H., Fonagy, P., & Schuengel, C. (2003). The importance of shared environment in mother-infant attachment security: A behavioral genetic study. Child Development, 74, 1769-1782.
In a sample of 157 monozygotic and dizygotic twins, genetic and environmental influences on infant attachment and temperament were quantified. Only unique environmental or error components could explain the variance in disorganized versus organized attachment as assessed in the Ainsworth Strange Situation Procedure. For secure versus nonsecure attachment, 52% of the variance in attachment security was explained by shared environment, and 48% of the variance was explained by unique environmental factors and measurement error. The role of genetic factors in attachment disorganization and attachment security was negligible. Genetic factors explained 77% of the variance in temperamental reactivity, and unique environmental factors and measurement error explained 23%. Differences in temperamental reactivity were not associated with attachment concordance.
Bimmel, N., Juffer, F., Van IJzendoorn, M.H., & Bakermans-Kranenburg, M.J. (2003). Problem behavior of internationally adopted adolescents: A review and meta-analysis. Harvard Review of Psychiatry, 1, 64-77.
In this paper we examine the prevalence of problem behaviors in samples of adolescents who were adopted from a foreign country as infants or young children. We reviewed ten studies and performed a meta-analysis, comparing 2317 internationally adopted adolescents with 14,345 nonadopted adolescents. Results indicate that internationally adopted adolescents exhibit more behavior problems than do nonadopted adolescents (d = 0.08; p = 0.02), with the difference seen in externalizing (d = 0.11; p = 0.00), but not in internalizing (d = 0.05; p = 0.12), behavior problems. Significantly more total behavior problems were seen in adopted than in nonadopted girls (d = 0.10; p = 0.03), but not in adopted boys compared to nonadopted ones (d = 0.07; p = 0.22). All differences, however, were small. The differences between adopted and nonadopted adolescents were somewhat larger when we considered behavior problems in the clinical range. The majority of the adopted adolescents are well adjusted and do not display significantly more problem behaviors than do their nonadopted peers.
Van IJzendoorn, M.H., Bakermans-Kranenburg, M.J., & Sagi, A. (2003). Are children of Holocaust survivors less well-adapted? No meta-analytic evidence for secondary traumatization. Journal of Traumatic Stress, 16, 459-469.
H. Keilson (1979) coined the term "sequential traumatization" for the accumulation of traumatic stresses confronting the Holocaust survivors before, during, and after the war. A central question is whether survivors were able to raise their children without transmitting the traumas of their past. Through a series of meta-analyses on 32 samples involving 4,418 participants, we tested the hypothesis of secondary traumatization in Holocaust survivor families. In the set of adequately designed nonclinical studies, no evidence for the influence of the parents' traumatic Holocaust experiences on their children was found. Secondary traumatization emerged only in studies on clinical participants, who were stressed for other reasons. A stress-diathesis model is used to interpret the absence of secondary traumatization in nonclinical offspring of Holocaust survivors.
Van IJzendoorn, M.H., & Bakermans-Kranenburg, M.J. (2003). Attachment disorders and disorganized attachment: similar and different. Attachment and Human Development, 5, 313-320.
The category of disorganised attachment was developed to account for the anomalous behaviour of abused infants and young children in the Strange Situation Procedure (Main & Solomon, 1990). Disorganised attachment has been shown to be indexed with clear-cut behavioural markers in relatively standard settings, and to have serious developmental consequences. The time has come to take the theory and research on disorganised attachment seriously, and to stimulate clinical investigations into the use of disorganised attachment in detecting, diagnosing and treating children with attachment disorders. Only part of the children classified as disorganised according to the current coding system should be considered clinically disturbed. One of the most important tasks is to determine the cut-off criterion for severe disorganisation of attachment that should be clinically treated.
Bakermans-Kranenburg, M.J., Van IJzendoorn, M.H. (in press). No association of the dopamine d4 receptor (drd4) and -521 c/t promoter polymorphisms with infant attachment disorganization. Attachment and Human Development.
In a first molecular genetic study Lakatos and colleagues (Lakatos et al., 2000; 2002) found an association between attachment disorganization and the dopamine D4 receptor (DRD4) gene polymorphism, in particular in the presence of the -521 T allele in the promotor region of the DRD4 gene. Replication of their study in a sample of 132 infants did not confirm the role of the DRD4 7+-allele and the -521C/T promoter gene in disorganized attachment. Although our sample was larger, and contained more children with CT or TT alleles, which enhanced the probability of finding the DRD4 and C/T interaction, the association was not found. Even when we combined our sample with the Lakatos et al. (2002) sample, the interaction effect of the DRD4 and -521 C/T polymorphisms on disorganized attachment was absent.
Van IJzendoorn, M.H., Vereijken, C.M.J.L., Bakermans-Kranenburg, M.J., & Riksen-Walraven, J.M.A. (in press). Is the Attachment Q-Sort a valid measure of attachment security in young children? Child Development.
The reliability and validity of the Attachment Q Sort (AQS; Waters & Deane, l985) was tested in a series of meta-analyses on 139 studies with 13,835 children. The observer AQS security score showed convergent validity with Strange Situation security (SSP; r = .31), and excellent predictive validity with sensitivity measures (r = .39). Its association with temperament was weaker (r = -.16) which supports the discriminant validity of the observer AQS. Studies on the stability of the observer AQS are still relatively scarce but they have yielded promising results (mean r = .28 (k = 4, n = 162). It is concluded that the observer AQS –but not the self-reported AQS-- is a valid measure of attachment.
Bakermans-Kranenburg, M.J., Van IJzendoorn, M.H., Bokhorst, C.L., & Schuengel, C. (in press). The importance of shared environment in infant-father attachment: A behavioral genetic study of the Attachment Q-Sort. Journal of Family Psychology.
In this first behavior genetic study on infant-father attachment, we estimated genetic and environmental influences on infant-father attachment behaviors and on temperamental dependency, both assessed with the Attachment Q-Sort (Vaughn & Waters, 1990; Waters, 1995). Mothers of mono- and dizygotic twins (N = 56 pairs) sorted the AQS with a focus on the infant’s behaviors in the presence of the father. Genetic modeling showed that attachment was largely explained by shared environmental (59%) and unique environmental (41%) factors (CE model). For dependency, genetic factors explained 66% of the variance, and unique environmental factors including measurement error 34% (AE model). Attachment to father appears to be, to a significant degree, a function of the environment that twins share.
Bakermans-Kranenburg, M.J., Van IJzendoorn, M.H., & Juffer, F. (in press). Disorganized infant attachment and preventive interventions: A review and meta-Analysis. Infant Mental Health Journal.
Infant disorganized attachment is a major risk factor for problematic stress management and later problem behavior. Can the emergence of attachment disorganization be prevented? The current narrative review and quantitative meta-analysis involves 15 preventive interventions (N = 842) that included infant disorganized attachment as an outcome measure. The effectiveness of the interventions ranged from negative to positive, with an overall effect size of d = 0.05 (n.s.). Effective interventions started after 6 months of the infant’s age (d = 0.23). Interventions that focused on sensitivity only were significantly more effective in reducing attachment disorganization (d = 0.24) than interventions that (also) focused on support and parent’s mental representations (d = -0.04). Most sample characteristics were not associated with differences in effect sizes, but studies with children at risk were more successful (d = 0.29) than studies with at-risk parents (d = -0.10), and studies on samples with higher percentages of disorganized attachment in the control groups were more effective (d = 0.31) than studies with lower percentages of disorganized children in the control group (d = -0.18). The meta-analysis shows that disorganized attachments may change as a side effect of sensitivity-focused interventions, but it also illustrates the need for interventions specifically focusing on the prevention of disorganization.
Rutgers, A.H., Bakermans-Kranenburg, M.J., Van IJzendoorn, M.H., & Van Berckelaer-Onnes, I.A. (in press). Autism and attachment: A meta-analytic review. Journal of Child Psychology and Psychiatry, 45.
Sixteen studies on attachment in children with autism were reviewed, and ten studies with data on observed attachment security (N = 287) were included in a quantitative meta-analysis. Despite the impairments of children with autism in reciprocal social interaction, the majority of the studies found evidence for attachment behaviours in these children. In four samples using the Strange Situation procedure the average percentage of secure attachments amounted to 53% (n = 72). Meta-analytic results showed that children with autism were significantly less securely attached to their parents than comparison children, and the combined effect size for this difference was moderate (r = .24). Children with autism displayed less attachment security than comparisons without autism, but this difference disappeared in samples with children with higher mental development, and in samples in which autism was mixed with less severe symptoms of autistic spectrum disorders. It is concluded that attachment security is compatible with autism, and can be assessed with Strange Situation type of procedures. The co-morbidity of autism and mental retardation appears to be associated with attachment insecurity.
Bakermans-Kranenburg, M.J., Van IJzendoorn, M.H., & Kroonenberg, P.M. (in press). Differences in attachment security between African-American and White children: Ethnicity or socio-economic status? Infant Behavior and Development.
The NICHD Early Childcare Research Network data set was used to examine differences in attachment security between African-American children (n = 142) and white children (n = 1002). African-American children’s mean score on the Attachment Q-sort (Waters, 1995) was substantially lower (.21) than that of white children’s (.30). The pattern of covariation between attachment security and predictor variables was similar in the African-American and white subgroups. In both groups, maternal sensitivity was the strongest predictor of attachment security. A mediational model explaining the difference in attachment security included income and sensitivity: African-American ethnicity was related to low income which through (in-)sensitivity affected the quality of the infant-mother attachment relationship (family stress model). Our findings on African-American mother-infant dyads support one of the basic tenets of attachment theory: the association between maternal sensitivity and attachment security. Children of African-American and white families in the USA may be exposed to culturally specific experiences, but these do not alter the relation between attachment security and pertinent predictor variables. Poverty may, however, seriously hamper maternal sensitivity.
Van IJzendoorn, M.H. & Bakermans-Kranenburg, M.J. (2002). Disorganized attachment and the dysregulation of negative emotions. In B. Zuckerman, A. Lieberman, & N. Fox (Eds.). Emotional regulation and developmental health: Infancy and early childhood (pp. 159-180). Pediatric Round Table. Johnson and Johnson Pediatric Institute L.L.C.
Bakermans-Kranenburg, M.J., van IJzendoorn, M.H., & Juffer, F. (2003). Preventive and therapeutic interventions in families with young children. In J.J. Ponzetti (Ed.), International Encyclopedia of Marriage and Family Relationships, 2nd edition (pp. 1642-1645).New York: Macmillan.
Van IJzendoorn, M.H.& Bakermans-Kranenburg, M.J. (2003). Maternal Sensitivity and Infant Temperament in the Formation of Attachment. In G. Bremner & A. Slater, (Eds.), Theories of Infant Development (pp. 233-257). Oxford: Blackwell.
Van IJzendoorn, M.H. & Bakermans-Kranenburg, M.J. (2003). Attachment. In R. Fernandez-Ballesteros (Ed.) The Encyclopedia of Psychological Assessment, Vol. 1 (pp. 101-106). London: Sage.
Juffer, F., Van IJzendoorn, M.H., & Bakermans-Kranenburg, M.J. (in press). Enhancing children’s socio-emotional development: A review of intervention studies. In D.M. Teti (Ed.), Handbook of Research Methods in Developmental Psychology. New York/Oxford: Blackwell Science.
Van IJzendoorn, M.H., Bakermans-Kranenburg, M.J., & Juffer, F. (in press). Beyond the Dodo Bird verdict: toward evidence-based interventions on sensitivity and early attachments. In L. Berlin, Attachment-based interventions. New York: Guilford.