Behavioral Inhibition and Stress Reactivity: The Moderating Role of Attachment Security

The role of the mother-toddler attachment relationship in moderating the relations between behavioral inhibition and changes in salivary cortisol levels in response to novel events was examined in 77 18-month-olds. Behavioral inhibition was determined by observing toddler inhibition of approach to several novel events. Attachment security to mother was assessed using the Ainsworth Strange Situation. Changes in salivary cortisol were used to index activity of the stress-sensitive hypothalamic-pituitary-adrenocortical (HPA) system. In addition, toddler coping behaviors and the behaviors used by mothers to help toddlers manage novel events were examined. Elevations in cortisol were found only for inhibited toddlers in insecure attachment relationships. Mothers in these relationships appeared to interfere with their toddlers' coping efforts. These results are discussed in the context of a coping model of the relations between temperament and stress reactivity.     

Quality of Toddler-Mother Attachment in Children with Down Syndrome: Limits to Interpretation of Strange Situation Behavior

Researchers studying social-emotional development have argued that primary attachment relationships, established by the end of the first year of life, are important organizing factors that influence the trajectory of development throughout childhood. Central to this argument is a dimension of "attachment security," along which attachments differ. For normally developing infants and toddlers, attachment security is assessed using the Ainsworth Strange Situation. However, it is not clear that this procedure is appropriate for evaluating attachment security in atypical populations. In this report, 3 samples of children with Down Syndrome (total N = 138) were assessed using the Strange Situation. The procedures were scored according to traditional protocols. Although the 3 samples differed with respect to chronological and developmental age, they showed basic similarity with respect to attachment variables. However, developmentally younger children were more difficult to classify using the standard scoring rules. Scores and classifications for the sample were compared to scores from a sample of normally developing children tested at about 12 months of age. Significant differences with respect to the distributions of cases to classification categories and with respect to the interactive scale scores suggest that the Strange Situation may be measuring different aspects of behavior for children with Down Syndrome, even when they are tested at similar developmental age levels.     

Expressions of the Attachment Relationship Outside of the Strange Situation

41 preterm infants and 38 full-term infants and their mothers were observed at home at 8 and 12 months of age and in the Strange Situation at 18 months in order to compare expressions of attachment relationships in these 2 settings. There was 84% concordance in the distinctions between secure and nonsecure classifications of the mother-infant relationship made at home at 12 months and in the Strange Situation. Classifications of avoidant relationships also displayed high concordance, but only 6 of the 15 dyads classified at home as ambivalent were classified in the same way in the Strange Situation. Mothers in secure relationships as assessed in the Strange Situation were rated as more sensitive at both 8 and 12 months than mothers in either avoidant or ambivalent relationships, whereas the sensitivity of mothers in these two nonsecure relationships did not differ significantly. Infants in secure relationships in the Strange Situation were characterized by more effective secure base behavior and more affective sharing and enjoyment of physical contact, and they were less fussy or difficult during the 12-month home observations.     

Parenting during the Second Year: Effects of Children's Age, Sex, and Attachment Classification

70 2-parent families with 12-month-old infants and 67 2-parent families with 18-month-old toddlers participated in the study. Mothers and fathers participated in separate interviews and filled out questionnaires on family and child behaviors. Mothers and their children participated in the Ainsworth Strange Situation, and the families were observed for a total of 4 hours in their homes. Families were compared on composite measures of family environment variables, parents' perception of their children, and on process variables from home observations. Family differences in environmental stress and marital adjustment showed no effects for attachment classifications, although parents of 12-month-olds reported greater marital adjustment and more pleasure in parenting than parents of 18-months-olds. Both mothers and fathers reported that children classified as resistant were more difficult on several temperament measures. During home observations, 12-month-old children received more positive responses from mothers, and 18-month-old children received more instructions and directions from both parents. Insecure boys (both avoidant and resistant) received the least instructions and directions from both parents, but insecure-avoidant girls received the most instruction from fathers.     

The Effects of Infant Child Care on Infant-Mother Attachment Security: Results of the NICHD Study of Early Child Care NICHD Early Child Care Research Network

The aims of this investigation were to determine whether Strange Situation attachment classifications were equally valid for infants with and without extensive child-care experience in the first year of life and whether early Child Care experience, alone or in combination with mother/child factors, was associated with attachment security, and specifically with insecure-avoidant attachment. Participants were 1,153 infants and their mothers at the 10 sites of the NICHD Study of Early Child Care. Mother were interviewed, given questionnairies, and observed in play and in the home when their infants were from 1 to 15 months of age; infants were observed in child care at 6 and 15 months and in the Strange Situation at 15 months. Infants with extensive Child Care experience did not differ from infants without child-care in the distress they exhibited during separations from mother in the Strange situation or in the confidence with which trained coders assigned them attachment classifications. There were no significant main effects of Child Care experience (quality, amount, age of entry, stability, or type of care) on attachment security or avoidance. There were, however, significant man effects of maternal sensitivity and responsiveness. Significant interaction effects revealed that infants were less likely to be secure when low maternal sensitivity/responsiveness was combined with poor quality child care, more than minimal amounts of child care, or more than one care arrangement. In addition, boys experiencing many hours in care and girls in minimal amounts of care were somewhat less likely to be securely attachment.     

Quality of infants' attachments to professional caregivers: relation to infant-parent attachment and day-care characteristics

75 infants (mean age 15 months) were observed 3 times in the Strange Situation with their professional caregivers, mothers, and fathers. Sensitivity of these attachment figures to the infant's signals during free play, as well as a number of day-care characteristics, were assessed. Attachment classification distribution of infant-caregiver dyads did not differ significantly from infant-mother or infant-father attachment classification distributions. The quality of infant-caregiver attachment was independent of both infant-mother and infant-father attachments. About 10% of the infants had 3 insecure attachments. Professional caregivers observed with more than 1 infant did not have similar types of attachment classifications to all infants with whom they were observed. Infants who were securely attached to their professional caregivers spent more hours per week in day-care, and came from a middle-class background. Their caregivers appeared to be younger and more sensitive during free play than caregivers with whom the infants developed an insecure relationship.     

Attachment security in infancy and early adulthood: a twenty-year longitudinal study

Sixty White middle-class infants were seen in the Ainsworth Strange Situation at 12 months of age; 50 of these participants (21 males, 29 females) were recontacted 20 years later and interviewed by using the Berkeley Adult Attachment Interview (AAI). The interviewers were blind to the participants' Strange Situation classifications. Overall, 72% of the infants received the same secure versus insecure attachment classification in early adulthood, K = .44, p < .001. As predicted by attachment theory, negative life events-defined as (1) loss of a parent, (2) parental divorce, (3) life-threatening illness of parent or child (e.g., diabetes, cancer, heart attack), (4) parental psychiatric disorder, and (5) physical or sexual abuse by a family member-were an important factor in change. Forty-four percent (8 of 18) of the infants whose mothers reported negative life events changed attachment classifications from infancy to early adulthood. Only 22% (7 of 32) of the infants whose mothers reported no such events changed classification, p < .05. These results support Bowlby's hypothesis that individual differences in attachment security can be stable across significant portions of the lifespan and yet remain open to revision in light of experience. The task now is to use a variety of research designs, measurement strategies, and study intervals to clarify the mechanisms underlying stability and change.     

Are Insecure-Avoidant Infants with Extensive Day-Care Experience Less Stressed by and More Independent in the Strange Situation?

In order to test the hypothesis that elevated ratings of avoidance and classifications of insecure-avoidant attachments of infants with extensive infant day-care histories may be the result of the fact that children with routine experiences of separation are less stressed by, and more independent in, the Strange Situation than more traditionally reared infants, 2 groups of 12-month-old infants with insecure-avoidant attachments were compared on 2 behavioral indices in each reunion-with-mother episode of the Strange Situation. 9 infants experienced less than 20 hours per week of nonparental care in their first year, and 11 infants experienced 20 or more hours of care. Contrary to propositions advanced by Clarke-Stewart, Thompson, and others, insecure-avoidant infants with extensive nonparental care experience whimpered, fussed, and cried more and engaged in object play less in each reunion episode than their insecure-avoidant counterparts with less nonparental care experience. These results are discussed in terms of the recent controversy surrounding infant day-care in the United States.     

Temperament and attachment security in the strange situation: an empirical rapprochement

In response to Frodi and Thompson's recent demonstration that infants classified A1-B2 in the Strange Situation differ significantly in emotional expression from infants classified B3-C2, several longitudinal data sets were examined to determine whether these group differences might be a function of infant temperament. Data from 3 separate samples revealed significant concordance between infant-mother and infant-father Strange Situation classifications when scored in terms of A1-B2 versus B3-C2, but not when scored in terms of the traditional A-B-C system. In addition, in 2 samples on which newborn behavioral data were available, A1-B2 infants displayed more autonomic stability than B3-C2 infants, and in one of the samples the former infants were more alert and positively responsive as newborns (with means in the same direction in Sample 2). Moreover, mothers of A1-B2 infants described their babies as less difficult to care for at 3 months of age. Considered together, these findings suggest that infant temperament affects the manner in which security or insecurity is expressed rather than whether or not the infant develops a secure or insecure attachment. These findings are discussed in terms of their implications for the study of the interactional antecedents and the developmental consequences of attachment security.     

Stability and Transmission of Attachment across Three Generations

Stability of adult attachment and transmission of attachment across 3 generations were examined in a longitudinal study of 96 infants, mothers, and maternal grandmothers. The Adult Attachment Interview (AAI) was used to assess attachment in mothers (during pregnancy and when infants were 11 months old) and grandmothers (any time during the study). The Strange Situation (SS) was used to assess attachment in infants at 12 months. Both the 3- and 4-category classification systems of the AAI and SS were used. Mothers' AAI classifications were stable over 12 months in 90% (3-category) and 77% (4-category) of mothers. Mothers' AAI classifications during pregnancy predicted infants' SS classifications in 81% (3-category) and 68% (4-category) of cases, and grandmothers' AAI classifications in 75% (3-category) and 49% (4-category) of cases. Using log-linear analysis, we show that a simple parent-to-child model accounts for transmission of attachment.     

Attachment behavior, attachment security, and temperament during infancy

In summary reviews and empirical research, investigators have suggested that attachment classifications derived from the Ainsworth Strange Situation may reflect variations along dimensions of temperament as well as, or perhaps instead of, individual differences with respect to infant-mother attachments. In this study, relations between temperament dimensions from the Infant Temperament Questionnaire (Revised) and Strange Situation behaviors were evaluated. Relations between the behavioral style scores and the categories of attachment quality were also tested. The hypothesis that temperamental difficulty would be related to negative emotionality, as indexed by infant distress during separation (but not during the reunions), was tested and supported. Neither the behavioral style dimensions nor the temperamental diagnoses (e.g., "easy" vs. "difficult") were associated significantly with attachment classifications. The results are consistent with previous findings that temperament measures do not predict attachment security. Nevertheless, certain behaviors indexing negative emotionality that may be observed in the context of the Strange Situation are related to temperamental variability.     

Parenting and Cortisol in Infancy Interactively Predict Conduct Problems and Callous–Unemotional Behaviors in Childhood

This study examines observed maternal sensitivity, harsh-intrusion, and mental-state talk in infancy as predictors of conduct problems (CP) and callous–unemotional (CU) behaviors in middle childhood, as well as the extent to which infants’ resting cortisol and cortisol reactivity moderate these associations. Using data from the Family Life Project (n = 1,292), results indicate that maternal sensitivity at 6 months predicts fewer CP at first grade, but only for infants who demonstrate high levels of cortisol reactivity. Maternal harsh intrusion predicts fewer empathic–prosocial behaviors, a component of CU behaviors, but only for infants who demonstrate high resting cortisol. Findings are discussed in the context of diathesis–stress and differential susceptibility models.     

Continuity and discontinuity of attachment from infancy through adolescence

This study reports relations between infant Ainsworth Strange Situation classifications, negative life events, and Adolescent Attachment Interview classifications. Overall, the stability of secure versus insecure classifications was 77%, and infant attachment classification was a significant predictor of adolescent attachment classification. Chi-square analyses indicate that negative life events are significantly related to change in attachment classification. The sample (n = 30) is drawn from the Family Lifestyles Project (FLS), an ongoing longitudinal study of children's development within the context of nonconventional family lifestyles. The distribution of family lifestyles within this study, unlike those in the full FLS sample, represent a higher proportion of conventional two-parent families (40%). There were no differences between adolescents reared in conventional or nonconventional families in the distribution of adolescent attachment security, the experience of negative life events, or the continuity of attachment from infancy through adolescence.     

Maternal employment in a family context: effects on infant-mother and infant-father attachments

The relation between resumption of full-time employment by mothers of infants under 6 months of age, and subsequent infant-mother and infant-father attachments, was examined in this study. Attachment classifications and ratings of reunion behavior with mother and with father in Ainsworth's Strange Situation at 12 months were obtained for 57 nonemployed-mother families and 40 employed-mother families. No relation emerged between maternal work status and the quality of infants' attachments to their mothers, indicating that early resumption of employment may not impede the development of secure infant-mother attachment. A significantly higher proportion of insecure attachments to fathers in employed-mother families was found for sons but not for daughters. Joint examination of the infants' attachments to both parents revealed a trend suggesting that in employed-mother families, boys were more likely to be insecurely attached to both parents than were girls in employed-mother families or infants of either sex in nonemployed-mother families. These patterns are discussed in light of differences in maternal and paternal sex-typing behavior and of evidence suggesting boys' vulnerability to psychosocial stress.     

Morning-to-afternoon increases in cortisol concentrations for infants and toddlers at child care: age differences and behavioral correlates

This study examined salivary cortisol, a stress-sensitive hypothalamic-pituitary-adrenocortical (HPA) axis hormone in 20 infants (12 females; M age = 10.8 months) and 35 toddlers (20 females; M age = 29.7 months) in full-day, center-based child care. Samples were taken at approximately 10:00 a.m. and 4:00 p.m. at child care and at home. At child care, 35% of infants and 71% of toddlers showed a rise in cortisol across the day; at home, 71% of infants and 64% of toddlers showed decreases. Toddlers who played more with peers exhibited lower cortisol. Controlling age, teacher-reported social fearfulness predicted higher afternoon cortisol and larger cortisol increases across the day at child care. This phenomenon may indicate context-specific activation of the HPA axis early in life.     

Emotional Determinants of Infant-Mother Attachment

The present study examined the assumption that emotion-related characteristics of mothers and infants contribute to the development of infant-mother attachment in the first year of life. Mothers' emotion and personality characteristics were assessed with expressive-behavior ratings and self-report scales. Infant characteristics were measured by emotion and temperament questionnaires (mother report) and objective coding of facial expressions of emotions. Attachment classifications were determined by means of the Strange Situation procedure, and a continuous-variable index of attachment security was derived by a discriminant function procedure. Mothers' emotion experiences, expressive behaviors, and personality traits were significant predictors of the level of security of the infant-mother attachment. Infants' expressive and temperamental characteristics as rated by their mothers were also significant predictors of attachment security.     

Biobehavioral Organization in Securely and Insecurely Attached Infants

Attachment research has shown the emergence of individual differences in the security of infant-mother attachment during the first year of life as well as their importance for later social-emotional development. A biobehavioral perspective may help settle disagreements about the validity and interpretation of 12-month-old infants' different behavioral patterns of attachment assessed by Ainsworth's Strange Situation. It was shown that, despite less overt distress in insecure-avoidant infants after short separations from the mother, overall cardiac measures indicate arousal patterns similar to the secure infants during separation. However, differences in cardiac response emerged with regard to object versus person orientation during reunion. Additionally, findings of increased cortisol in both insecure-avoidant and disorganized infants support the theoretical interpretation that these infants, in contrast to secure infants, lack an appropriate coping strategy.     

The Effect of Hearing Impairment on the Quality of Attachment and Mother-Toddler Interaction

In the present study, 41 hearing impaired and 41 hearing toddlers together with their hearing mothers were observed in Ainsworth's Strange Situation and during free play. Both security of attachment and ratings of maternal and toddler behavior during free play were remarkably similar for the hearing impaired and hearing dyads. In addition, security of attachment was related to the ratings of maternal and toddler behavior in a similar way for the hearing impaired and hearing toddlers. The results suggest that development of a secure attachment and maintaining a good mother-toddler relationship does not depend on normal language development during the toddler years.     

Infant – Mother Attachment among the Dogon of Mali

This study of mothers and infants from the Dogon ethnic group of Mali, West Africa examined three attachment hypotheses: (1) that infant attachment security is linked to the quality of mother-infant communication, (2) that mothers of secure infants respond more sensitively to their infants than do mothers of insecure infants, and (3) that infant disorganization is linked to maternal frightened or frightening behaviors. Participants were 27 mother-infant pairs from a rural town and 15 mother-infant pairs from two agrarian villages; infants ranged in age from 10 to 12.5 months at the first assessment. The distribution of the Strange Situation classifications was 67% secure, 0% avoidant, 8% resistant, and 25% disorganized. Infant attachment security was significantly related to the quality of mother-infant communication as observed in a well-infant exam. The correlation between infant attachment security ratings and maternal sensitivity (assessed in the home) was modest and approached significance. Mothers of disorganized infants had significantly higher ratings of frightened or frightening behaviors. Maternal sensitivity predicted little of the variance in infant security; however, the addition of the frightened/frightening variable in the regression equation tripled the explained variance. The findings are discussed in light of Dogon childrearing practices and key tenets of attachment theory.