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Background: Lateral ventricular volume (LVV) enlargement has been repeatedly linked to schizophrenia; yet, what biological factors shape LVV during early development remain unclear. DNA methylation (DNAm), an essential process for neurodevelopment that is altered in schizophrenia, is a key molecular system of interest., Methods: In this study, we conducted the first epigenome-wide association study of neonatal DNAm in cord blood with LVV in childhood (measured using T1-weighted brain scans at 10 years), based on data from a large population-based birth cohort, the Generation R Study (N = 840). Employing both probe-level and methylation profile score (MPS) approaches, we further examined whether epigenetic modifications identified at birth in cord blood are: (a) also observed cross-sectionally in childhood using peripheral blood DNAm at age of 10 years (Generation R, N = 370) and (b) prospectively associated with LVV measured in young adulthood in an all-male sample from the Avon Longitudinal Study of Parents and Children (ALSPAC, N = 114)., Results: At birth, DNAm levels at four CpGs (annotated to potassium channel tetramerization domain containing 3, KCTD3; SHH signaling and ciliogenesis regulator, SDCCAG8; glutaredoxin, GLRX) prospectively associated with childhood LVV after genome-wide correction; these genes have been implicated in brain development and psychiatric traits including schizophrenia. An MPS capturing a broader epigenetic profile of LVV - but not individual top hits - showed significant cross-sectional associations with LVV in childhood in Generation R and prospectively associated with LVV in early adulthood within ALSPAC., Conclusions: This study finds suggestive evidence that DNAm at birth prospectively associates with LVV at different life stages, albeit with small effect sizes. The prediction of MPS on LVV in a childhood sample and an independent male adult sample further underscores the stability and reproducibility of DNAm as a potential marker for LVV. Future studies with larger samples and comparable time points across development are needed to further elucidate how DNAm associates with this clinically relevant brain structure and risk for neuropsychiatric disorders, and what factors explain the identified DNAm profile of LVV at birth., (© 2023 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.)

We examined the relative contribution of genetic, shared environmental and non-shared environmental factors to the covariance between parental sensitivity and limit-setting observed twice in a longitudinal study using a child-based twin design. Parental sensitivity and parental limit-setting were observed in 236 parents with each of their same-sex toddler twin children (M age  = 3.8 years; 58% monozygotic). Bivariate behavioral genetic models indicated substantial effects of similar shared environmental factors on parental sensitivity and limit-setting and on the overlap within sensitivity and limit-setting across 1 year. Moderate child-driven genetic effects were found for parental limit-setting in year 1 and across 1 year. Genetic child factors contributing to explaining the variance in limit-setting over time were the same, whereas shared environmental factors showed some overlap., (© 2020 The Authors. Child Development published by Wiley Periodicals LLC on behalf of Society for Research in Child Development.)

Child maltreatment in the family context is a prevalent and pervasive phenomenon in many modern societies. The global perpetration of child abuse and neglect stands in stark contrast to its almost universal condemnation as exemplified in the United Nation's Convention on the Rights of the Child. Much work has been devoted to the task of prevention, yet a grand synthesis of the literature is missing. Focusing on two core elements of prevention, that is, antecedents for maltreatment and the effectiveness of (preventative) interventions, we performed an umbrella review of meta-analyses published between January 1, 2014, and December 17, 2018. Meta-analyses were systematically collected, assessed, and integrated following a uniform approach to allow their comparison across domains. From this analysis of thousands of studies including almost 1.5 million participants, the following risk factors were derived: parental experience of maltreatment in his or her own childhood (d = .47), low socioeconomic status of the family (d = .34), dependent and aggressive parental personality (d = .45), intimate partner violence (d = .41), and higher baseline autonomic nervous system activity (d = .24). The effect size for autonomic stress reactivity was not significant (d = -.10). The umbrella review of interventions to prevent or reduce child maltreatment showed modest intervention effectiveness (d = .23 for interventions targeting child abuse potential or families with self-reported maltreatment and d = .27 for officially reported child maltreatment cases). Despite numerous studies on child maltreatment, some large gaps in our knowledge of antecedents exist. Neurobiological antecedents should receive more research investment. Differential susceptibility theory may shed more light on questions aimed at breaking the intergenerational transmission of maltreatment and on the modest (preventive) intervention effects. In combination with family-based interaction-focused interventions, large-scale socioeconomic experiments such as cash transfer trials and experiments with vouchers to move to a lower-poverty area might be tested to prevent or reduce child maltreatment. Prevalence, antecedents, and preventive interventions of prenatal maltreatment deserve continuing scientific, clinical, and policy attention., (© 2019 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.)

The evidence for negative influences of maternal stress during pregnancy on child cognition remains inconclusive. This study tested the association between maternal prenatal stress and child intelligence in 4,251 mother-child dyads from a multiethnic population-based cohort in the Netherlands. A latent factor of prenatal stress was constructed, and child IQ was tested at age 6 years. In Dutch and Caribbean participants, prenatal stress was not associated with child IQ after adjustment for maternal IQ and socioeconomic status. In other ethnicities no association was found; only in the Moroccan/Turkish group a small negative association between prenatal stress and child IQ was observed. These results suggest that prenatal stress does not predict child IQ, except in children from less acculturated minority groups., (© 2018 Society for Research in Child Development.)

This paper serves as an Introduction by the co-editors to a Special Section of Child Development entitled "Meta-analysis and Individual Participant Data Synthesis in Child Development." First, the co-editors emphasize that the work contained in the Special Section was selected to highlight the value of meta-analysis not only for synthesizing study-level published and unpublished data but also as regards its ability to support programmatic, replicable, and cumulative developmental science. Second, the co-editors identify some of the cross-cutting themes of the papers featured in the Special Section, including the value of meta-analysis for summarizing and interrogating the full range of developmental science and in potentially transforming conventional wisdom in given domains along with the importance of recent innovations for improving standard meta-analytic practice-particularly in the context of developmental questions. Emphasized especially are contributions to the Special Section that extend classic meta-analysis to individual participant data synthesis., (© 2018 Society for Research in Child Development.)

Parents' attachment representations and child-parent attachment have been shown to be associated, but these associations vary across populations (Verhage et al., 2016). The current study examined whether ecological factors may explain variability in the strength of intergenerational transmission of attachment, using individual participant data (IPD) meta-analysis. Analyses on 4,396 parent-child dyads (58 studies, child age 11-96 months) revealed a combined effect size of r = .29. IPD meta-analyses revealed that effect sizes for the transmission of autonomous-secure representations to secure attachments were weaker under risk conditions and weaker in adolescent parent-child dyads, whereas transmission was stronger for older children. Findings support the ecological constraints hypothesis on attachment transmission. Implications for attachment theory and the use of IPD meta-analysis are discussed., (© 2018 The Authors. Child Development published by Wiley Periodicals, Inc. on behalf of Society for Research in Child Development.)

This meta-analytic review examines the association between early attachment (assessed at 1-5 years) and child temperament (assessed at birth-12 years), and compares the strength of this association with recently documented meta-analytic associations between early attachment and social competence, externalizing behavior, and internalizing symptoms. Based on 109 independent samples (N = 11,440) of diverse socioeconomic and ethnic backgrounds, temperament was weakly associated with attachment (in)security (d = .14, CI [0.08, 0.19]) but modestly associated with resistant attachment (d = .30, CI [0.21, 0.40]). Temperament was not significantly associated with avoidant (d = .10, CI [-0.02, 0.19]) or disorganized (d = .11, CI [-0.03, 0.25]) attachment. Across developmental domains, early attachment security was more strongly associated with social competence and externalizing behaviors than internalizing symptoms and temperament., (© 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.)

To investigate potential infant-related antecedents characterizing later attachment security, this study tested whether attention to facial expressions, assessed with an eye-tracking paradigm at 7 months of age (N = 73), predicted infant-mother attachment in the Strange Situation Procedure at 14 months. Attention to fearful faces at 7 months predicted attachment security, with a smaller attentional bias to fearful expressions associated with insecure attachment. Attachment disorganization in particular was linked to an absence of the age-typical attentional bias to fear. These data provide the first evidence linking infants' attentional bias to negative facial expressions with attachment formation and suggest reduced sensitivity to facial expressions of negative emotion as a testable trait that could link attachment disorganization with later behavioral outcomes., (© 2015 The Authors. Child Development published by Wiley Periodicals, Inc. on behalf of Society for Research in Child Development.)

Background: Obesity is a growing problem even in very young childhood, resulting in high costs for individuals and society. As a response, numerous obesity prevention and intervention programs have been developed. Previous research has shown that early intervention programs are more effective when parents are involved, but the effectiveness of specific aspects of programs with parental involvement has not been investigated. This meta-analysis aims to investigate the features related to the effectiveness of different types of obesity intervention programs involving parents and targeting young children (0-6-year-olds)., Methods: The Web of Science, PubMed, PsycInfo, CINAHL, and ERIC databases were searched for childhood obesity prevention and intervention programs involving parents. Data were analyzed using the Comprehensive Meta-analysis (CMA) software., Results: Fifty studies with effect sizes measured at short-term follow-up (within 3 months from the end of the intervention) and 26 studies with effect sizes measured at long-term follow-up (all reported in a total of 49 publications) were identified. The combined effect size of interventions was small but significant at short-term follow-up (d = .08, p < .01). The results suggested the presence of a potential publication bias in studies providing results at long-term follow-up, with a nonsignificant adjusted effect size (d = .02), which indicated that obesity interventions were not effective at long-term follow-up. Multivariate meta-regression analyses showed that interventions were more effective when including either interactive sessions or educational materials as opposed to those including both interactive sessions and noninteractive educational materials. No other moderators regarding sample characteristics, study design, or methodological quality were significant., Conclusion: Interventions targeting young children that require parental involvement are effective at short-term follow-up, specifically when interventions include one mode of intervention rather than two. However, results were not retained in the long run., (© 2014 Association for Child and Adolescent Mental Health.)

Background: Little is known about the genetic determinants of sensitive parenting. Two earlier studies examined the effect of the serotonin transporter polymorphism (5-HTTLPR) on sensitive parenting, but reported opposite results. In a large cohort we further examined whether 5-HTTLPR is a predictor of observed maternal sensitivity and whether observed child social fearfulness moderates the effect of 5-HTTLPR on maternal sensitivity., Methods: The population-based cohort consisted of 767 mother-child dyads. Maternal sensitivity was repeatedly observed at the child's age of 14 months, 36 months and 48 months. Sensitivity was coded using the Ainsworth's rating scales for sensitivity and cooperation and the revised Erickson rating scales for Supportive presence and Intrusiveness. Child social fearfulness was observed using the Stranger Approach episode of the Laboratory Temperament Assessment Battery at 36 months., Results: Repeated measurement analyses showed a consistent main effect of maternal 5-HTTLPR on sensitivity; mothers carrying the S-allele were more sensitive toward their children (p = .005). This effect was not explained by the child's 5-HTTLPR genotype. We found no evidence that child social fearfulness moderated the effect of 5-HTTLPR on sensitivity., Conclusions: This study suggests that variations in maternal 5-HTTLPR genotype appear to be involved in the etiology of parenting behavior. The observed effects of this genetic variation are consistent with the notion that parenting may have a genetic component, but large studies are needed to find the specific small molecular effects., (© 2014 The Authors. Journal of Child Psychology and Psychiatry. © 2014 Association for Child and Adolescent Mental Health.)

Background: Low heart rate predicts externalising and delinquent behaviour in adults, adolescents and school-age children. In younger children the evidence is less clear. Moreover, the specificity of the relation between the autonomic nervous system and different forms of externalising behaviour is uncertain. We investigated the longitudinal relation between resting mean heart rate and different externalising behaviours., Methods: In 412 children of the Generation R Study, we measured resting mean heart rate at 14 months. At 3 years, child problem behaviour was assessed by the mother with the Child Behavior Checklist. In a gift delay task, we observed whether children were compliant and whether they lied about their noncompliance. The association of heart rate with behaviour was contrasted with the effect of harsh parenting., Results: In our main analysis, we examined the association between heart rate and reported and observed child behaviour. For comparison, the association of heart rate with behaviour was contrasted with the effect of harsh parenting. Mean heart rate was positively associated with Anxious/Depressed scale scores (β = .1, 95% CI = 0.01; 0.2, p = .04), but not with Aggressive Behaviour (β = .02; 95% CI = −0.1; 0.1, p = .8) nor Attention Problem scale scores (β = .08, 95% CI = −0.3; 0.5, p = .8). We could not demonstrate an association between mean heart rate and noncompliance during the gift delay task (OR = 1.14, 95% CI = 0.9; 1.1, p = .2), but lower heart rate predicted higher odds of the child lying (OR = 0.56, 95% CI = 0.3; 0.9, p = .03). In contrast, harsh parenting was associated with mother-reported Aggressive Behaviour (β = .7, 95% CI = 0.4; 0.9, p < .001) and Attention Problems (β = .2, 95% CI = 0.1; 0.3, p < .001), but not with observed lying (OR = 1.03, 95% CI = 0.8; 1.4, p = .8)., Conclusions: Lower resting mean heart rate at age 14 months predicts low anxiety symptoms and higher odds of lying at age 3 years. Low resting mean heart rate may be less an indicator of early childhood aggression than of fearless behaviour.

This meta-analytic review examines the association between attachment and internalizing symptomatology during childhood, and compares the strength of this association with that for externalizing symptomatology. Based on 42 independent samples (N = 4,614), the association between insecurity and internalizing symptoms was small, yet significant (d = 0.15, CI 0.06~0.25) and not moderated by assessment age of internalizing problems. Avoidance, but not resistance (d = 0.03, CI -0.11~0.17) or disorganization (d = 0.08, CI -0.06~0.22), was significantly associated with internalizing symptoms (d = 0.17, CI 0.03~0.31). Insecurity and disorganization were more strongly associated with externalizing than internalizing symptoms. Discussion focuses on the significance of attachment for the development of internalizing versus externalizing symptomatology., (© 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.)

Background and Methods: In two birth cohort studies with genetic, sensitive parenting, and attachment data of more than 1,000 infants in total, we tested main and interaction effects of candidate genes involved in the dopamine, serotonin, and oxytocin systems (DRD4, DRD2, COMT, 5-HTT, OXTR) on attachment security and disorganization. Parenting was assessed using observational rating scales for parental sensitivity (Ainsworth, Bell, & Stayton, 1974), and infant attachment was assessed with the Strange Situation Procedure., Results: We found no consistent additive genetic associations for attachment security and attachment disorganization. However, specific tests revealed evidence for a codominant risk model for COMT Val158Met, consistent across both samples. Children with the Val/Met genotype showed higher disorganization scores (combined effect size d = .22, CI = .10-.34, p < .001). Gene-by-environment interaction effects were not replicable across the two samples., Conclusions: This unexpected finding might be explained by a broader range of plasticity in heterozygotes, which may increase susceptibility to environmental influences or to dysregulation of emotional arousal. This study is unique in combining the two largest attachment cohorts with molecular genetic and observed rearing environment data to date., (© 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Background: The rearing environment of human immunodeficiency virus (HIV)-infected children is often compromised, putting these children at additional risks. Positive caregiving may ameliorate the impact of adverse circumstances and promote attachment security. The goal of the present study was to examine the attachment relationships of HIV-infected children in biological families and institutions; to examine the effects of HIV infection and institutional rearing on attachment security and indiscriminate friendliness; and to assess the role of caregiving in the face of HIV-related adversities., Methods: We studied 64 Ukrainian uninfected and HIV-infected children reared in families and institutions (mean age 50.9 months). Physical and cognitive development of children as well as attachment-related domains and indiscriminate friendliness were assessed., Results: Institutional care but not the presence of HIV was associated with lower levels of attachment security and higher levels of indiscriminate friendliness. On average, the level of indiscriminate friendliness among institution-reared children was more than twice as high as among family-reared children. Only 24% of institution-reared children had clearly developed attachment patterns, as opposed to 97% among family-reared children. Controlling for physical and cognitive development, type of care (institution or family), and HIV status, positive caregiving was associated with higher levels of attachment security. Indiscriminate friendliness was associated with lower levels of attachment security among family-reared children, but with higher levels of positive caregiving among institution-reared children., Conclusions: Etiology and function of indiscriminate friendliness may differ for family-reared versus institution-reared children. The findings of this study suggest the necessity of early interventions improving the quality of care for HIV-infected children., (© 2010 The Authors. Journal of Child Psychology and Psychiatry. © 2010 Association for Child and Adolescent Mental Health.)

This study addresses the extent to which insecure and disorganized attachments increase risk for externalizing problems using meta-analysis. From 69 samples (N = 5,947), the association between insecurity and externalizing problems was significant, d = 0.31 (95% CI: 0.23, 0.40). Larger effects were found for boys (d = 0.35), clinical samples (d = 0.49), and from observation-based outcome assessments (d = 0.58). Larger effects were found for attachment assessments other than the Strange Situation. Overall, disorganized children appeared at elevated risk (d = 0.34, 95% CI: 0.18, 0.50), with weaker effects for avoidance (d = 0.12, 95% CI: 0.03, 0.21) and resistance (d = 0.11, 95% CI: -0.04, 0.26). The results are discussed in terms of the potential significance of attachment for mental health.

To study the effects of perinatal HIV-1 infection and early institutional rearing on the physical and cognitive development of children, 64 Ukrainian uninfected and HIV-infected institutionalized and family-reared children were examined (mean age = 50.9 months). Both HIV infection and institutional care were related to delays in physical and cognitive development, with a larger effect of the rearing environment. Family care, even of compromised quality, was found to be more favorable for children's physical and cognitive development than institutional care. The impact of the quality of child care on physical and cognitive development is discussed in light of future interventions.

The current study examined whether adolescents' attachment representations were associated with differences in emotion regulation during the Adult Attachment Interview (AAI; C. George, N. Kaplan, & M. Main, 1996) and during a mother-adolescent conflict interaction task (Family Interaction Task [FIT]; J. P. Allen et al., 2003). Participants were one hundred and fifty-six 14-year-old adolescents. Dismissing adolescents showed less interbeat interval (IBI) reactivity (indicating less stress) during the AAI than secure adolescents. However, during the FIT, dismissing adolescents showed more IBI reactivity. No differences in physiological reactivity were found between individuals with resolved or unresolved loss or trauma during the AAI or FIT. The results indicate that dismissing adolescents may effectively use a defensive strategy during the AAI but less so in direct conflict interaction with their attachment figure.

Gene-environment interactions interpreted in terms of differential susceptibility may play a large part in the explanation of individual differences in human development. Reviewing studies on the behavioral and molecular genetics of attachment, we present evidence for interactions between genetic and environmental factors explaining individual differences in attachment security and disorganization. In particular, the DRD4 7-repeat polymorphism seems associated with an increased risk for disorganized attachment, but only when combined with environmental risk. Gene-environment (G x E) interactions may be interpreted as genetic vulnerability or differential susceptibility. We found support for the differential susceptibility hypothesis predicting not only more negative outcomes for susceptible children in unfavorable environments, but also positive outcomes for susceptible children in favorable environments.

This study on sensitivity and attachment included 55 toddlers and their parents. Samples included children with autism spectrum disorder (ASD), mental retardation, language delay, and typical development. Children were diagnosed at 4 years of age. Two years before diagnosis, attachment was assessed with the Strange Situation procedure, and parental sensitivity and child involvement during free play were assessed with the Emotional Availability Scale. Parents of children with ASD were equally sensitive as parents of children without ASD, but their children showed more attachment disorganization and less child involvement. More sensitive parents had more secure children, but only in the group without ASD. Less severe autistic symptoms in the social domain predicted more attachment security. Autism challenges the validity of attachment theory.

Background: Adopted children have been said to be difficult children, scarred by their past experiences in maltreating families or neglecting orphanages, or by genetic or pre- and perinatal problems. Is (domestic or international) adoption an effective intervention in the developmental domains of physical growth, attachment security, cognitive development and school achievement, self-esteem, and behaviour problems?, Method: Through a series of meta-analyses on more than 270 studies that include more than 230,000 adopted and non-adopted children and their parents an adoption catch-up model was tested., Results: Although catch-up with current peers was incomplete in some developmental domains (in particular, physical growth and attachment), adopted children largely outperformed their peers left behind. Adoptions before 12 months of age were associated with more complete catch-up than later adoptions for height, attachment, and school achievement. International adoptions did not lead to lower rates of catch-up than domestic adoptions in most developmental domains., Conclusions: It is concluded that adoption is an effective intervention leading to massive catch-up. Domestic and international adoptions can be justified on ethical grounds if no other solutions are available. Humans are adapted to adopt, and adoption demonstrates the plasticity of child development.

Background: Research suggests that institutional care has long-lasting effects on children. However, no study has longitudinally studied infants in an institution and their subsequent development at age four., Methods: Sixty-one adopted children aged four years who had spent their first two years of life in an institution were compared to 39 children reared in their own two-parent families. Cognitive development, security of attachment, shyness, children's emotional understanding and behavioural problems were examined in both groups. Parental health and stress were also assessed., Results: At four years adopted children still had lower scores on cognitive development, were less secure, and less able to understand emotions than family-reared children. Children with a secure attachment type in infancy were found to be less secure at age four, compared with those who were classified in infancy as having an insecure attachment type. Their physical development had recovered, they were less shy, had no behavioural problems and no problems in the relationship with their teacher., Conclusions: Early residential group care has long-lasting effects on important socio-emotional and cognitive aspects of preschool children's development.

Background: This study investigated the occurrence, cross-informant agreement, 1-year stability, and context characteristics of externalizing behaviors in 12-month-old children, as compared to 24- and 36-month-olds., Method: In a general population sample of 786 12-month-olds, 720 24-month-olds, and 744 36-month-olds, the CBCL/ 1(1/2)-5 was obtained from mothers and fathers and again one year later for a subsample of 307 children. Mothers of 1,831 children also provided complete data on child, mother, and family characteristics., Results: Over three-fourths of the externalizing behaviors occurred in more than 10% of 12-month-olds, over one-third of the items in more than 25%. For almost all externalizing behaviors, the occurrence was significantly lower in 12-month-olds compared to 24- and 36-month-old children. Mother-father agreement and 1-year stability of externalizing behaviors in 12-month-old children were significant, but generally somewhat lower than in 24- and 36-month-olds. Context characteristics were related to externalizing behaviors in 12-month-olds as well as in older children. Some associations were less pronounced in 12-month-old children, but the overall pattern of correlates was similar across age groups., Conclusions: The results of this study show that externalizing behaviors in 12-month-old children merit further research and can be assessed with the CBCL in a valid way.

This study examines the prevalence, stability, and development of physical aggression, as reported by mothers and fathers, in a sample of children initially recruited at 12, 24, and 36 months (N=2,253) and in a subsample followed up 1 year later (n=271) in a cross-sequential design. Physical aggression occurred in 12-month-olds, but significantly more often in 24- and 36-month-olds. The rates of physically aggressive behaviors increased in the 2nd year of life, and declined from the 3rd birthday onward. Stabilities were moderate for 12-month-olds and high for 24- and 36-month-olds. At the ages of 24 and 36 months, boys were more aggressive than girls. The results confirm and extend R.E. Tremblay's (2004) hypothesis about the early development of physical aggression.

Background: As infant disorganized attachment is a serious risk factor for later child psychopathology, it is important to examine whether attachment disorganization can be prevented or reduced., Method: In a randomized intervention study involving 130 families with 6-month-old adopted infants, two attachment-based intervention programs were tested. In the first program, mothers were provided a personal book, and in the second program mothers received the same personal book and three home-based sessions of video feedback. The third group did not receive intervention (control group)., Results: The intervention with video feedback and the personal book resulted in enhanced maternal sensitive responsiveness (d=.65). Children of mothers who received this intervention were less likely to be classified as disorganized attached at the age of 12 months (d=.46), and received lower scores on the rating scale for disorganization than children in the control group (d=.62). In the book-only intervention group children showed lower disorganization ratings compared to the control group, but no effect on the number of infants with disorganized attachment classifications was found., Conclusion: Our short-term preventive intervention program with video feedback and a book lowered the rate of disorganized attachment. The effectiveness of our intervention documents the importance of parenting in the development of infant attachment disorganization.

Method: 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., Results: 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., Conclusions: 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.

The reliability and validity of the Attachment Q Sort (AQS; Waters & Deane, 1985) 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 procedure (SSP) security (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., (Copyright 2004 Society for Research in Child Development, Inc.)

Background: The attachment relationships of infants reared in residential group care from birth, and links between attachment quality and psychosocial development and caregiver sensitivity were studied, with 86 infants reared in group care and 41 infants reared in their own two-parent families who attended day-care centres., Methods: Attachment, cognitive development, temperament, and observed social behaviour of the two groups were studied, as was the quality of care by caregivers and mothers., Results: Sixty-six per cent of infants reared in residential group care showed disorganised attachment to their caregivers, compared with 25% of control infants; 24% of group care infants were securely attached, compared with 41% of control infants. The two groups differed in cognitive development, in temperament and observed social behaviour. Within the residential group care babies, those that were securely attached were observed to express more frequent positive affect and social behaviour, and to initiate more frequent interaction with their caregivers., Conclusions: Residential care affected all aspects of the infants' development and was linked to a high rate of disorganised attachment.

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.

Three studies examined associations between early child care and child outcomes among families different from those in the National Institute of Child Health and Human Development (NICHD) Early Child Care Research Network study. Results suggest that quality is an important influence on children's development and may be an important moderator of the amount of time in care. Thus, the generalizability of the NICHD findings may hinge on the context in which those results were obtained. These studies, conducted in three national contexts, with different regulatory climates, ranges of child care quality, and a diversity of family characteristics, suggest a need for more complete estimates of how both quality and quantity of child care may influence a range of young children's developmental outcomes.