W. Roger Mills-Koonce

Parasympathetic and sympathetic responses to the strange situation in infants and mothers from avoidant and securely attached dyads

Vagal reactivity and salivary alpha-amylase (sAA) were assessed in infants (M age = 13.55 months) and their mothers during the Strange Situation Paradigm (SSP) to investigate differences in physiological responses in a sample of insecure-avoidant and securely-attached dyads (N = 132). Infants classified as insecure-avoidant had significantly higher vagal withdrawal during the SSP and higher sAA overall, suggesting that the avoidant attachment pattern is associated with a greater allostatic load. During separation episodes of the SSP, all mothers showed significant vagal withdrawal, suggesting greater attempts at regulation. During the last reunion, typically the most stressful episode for infants, mothers of secure infants showed greater vagal withdrawal than mothers of insecure-avoidant infants, suggesting greater attempts by these mothers at interactive repair. Results for mothers and infants supported the allostatic load theory.

Gene-Environment Contributions to the Development of Infant Vagal Reactivity: The Interaction of Dopamine and Maternal Sensitivity

This study investigated dopamine receptor genes (DRD2 and DRD4) and maternal sensitivity as predictors of infant respiratory sinus arrhythmia (RSA) and RSA reactivity, purported indices of vagal tone and vagal regulation, in a challenge task at 3, 6, and 12 months in 173 infant-mother dyads. Hierarchical linear modeling (HLM) revealed that at 3 and 6 months, RSA withdrawal in response to maternal separation was greater (suggesting expected physiological regulation) in infants without the DRD2 risk allele than those with the risk allele. At 12 months, infants with the risk allele who were also exposed to maternal sensitivity showed levels of RSA withdrawal comparable to infants who were not at genetic risk. Findings demonstrate the importance of developmental analysis of gene-environment interaction.

Bidirectional genetic and environmental influences on mother and child behavior: The family system as the unit of analyses

Family systems theory proposes that an individuals functioning depends on interactive processes within the self and within the context of dyadic family subsystems. Previous research on these processes has focused largely on behavioral, cognitive, and psychophysiological properties of the individual and the dyad. The goals of this study were to explore genetic and environmental interactions within the family system by examining how the dopamine receptor D2 gene (DRD2) A1+ polymorphism in mothers and children relates to maternal sensitivity, how maternal and child characteristics might mediate those effects, and whether maternal sensitivity moderates the association between DRD2 A1+ and child affective problems. Evidence is found for an evocative effect of child polymorphism on parenting behavior, and for a moderating effect of child polymorphism on the association between maternal sensitivity and later child affective problems. Findings are discussed from a family systems perspective, highlighting the role of the family as a context for gene expression in both mothers and children.

Interdependence of Parenting of Mothers and Fathers of Infants

This study examined the relations among parenting behaviors of 97 coresident mothers and fathers of infants during a dyadic free-play setting. The authors examined the extent to which observed sensitive and intrusive parenting behaviors in mother-child and father-child dyads were related and how perceived marital quality may be associated with the similarity between maternal and paternal parenting behaviors. The authors found support for interdependence of parenting by mothers and fathers. High perceived marital quality was associated with interdependence of sensitive parenting behaviors in mother-infant and father-infant interactions. Negative parenting behaviors by mothers and fathers were interrelated regardless of marital quality. The findings highlight the importance of studying parenting by mothers and fathers as embedded within particular family systems.

The Family Model Stress and Maternal Psychological Symptoms: Mediated Pathways from Economic Hardship to Parenting

Although much of the extant research on low-income families has targeted parental depression as the predominant psychological response to economic hardship, the current study examined a range of maternal psychological symptoms that may mediate the relations between early economic pressure and later parenting behaviors. A family stress model was examined using data from 1,142 mothers living in 2 areas of high rural poverty, focusing on the infancy through toddlerhood period. Maternal questionnaires and observations of mother-child interactions were collected across 4 time points (6, 15, 24, and 36 months). Results from structural equation analyses indicated that early economic pressure was significantly related to a variety of symptoms (depression, hostility, anxiety, and somatization), but only depression and somatization were significantly related to decreased levels of sensitive, supportive parenting behaviors. In contrast, anxiety was positively associated with sensitive parenting. Depression and anxiety were both found to mediate the relations between economic pressure and sensitive parenting behaviors. Results further suggest that mothers did not experience change in objective economic hardship over time but did experience a small decrease in economic pressure. Discussion centers on the apparent indirect influence of early economic hardship on later psychological symptoms and parenting behaviors, as well as detailing the need for broader and more complex perspectives on maternal psychological responses that arise as a result of economic disadvantage.

Psychophysiological correlates of parenting behavior in mothers of young children

This study investigated HPA and vagal functioning as correlates of parenting in mothers of 175 six-month-old children. Salivary cortisol indexed HPA functioning and respiratory sinus arrhythmia (RSA) reduction indexed vagal regulation. Positive engagement and negative intrusiveness were observed during the Face-to-Face Still Face Paradigm (FFSFP) reunion and a semi-structured free play episode. Mixed modeling was used to examine differences in maternal behaviors across contexts as a function of psychophysiology. Main effects of cortisol levels, as well as interactions with RSA reduction and context, predicted negative intrusiveness. Mothers with high cortisol exhibited more negative intrusiveness if they also had lower RSA reduction. Mothers were also less negatively intrusive during the FFSFP than the free play if they had lower cortisol levels. There were no associations between psychophysiological measures and positive engagement. The findings suggest: (1) that parenting behaviors are associated with maternal stress physiology; (2) considerations of single physiological systems related to parenting behaviors may be incomplete; and (3) type and context of behaviors must be considered when examining biobehavioral associations with parenting.

Father Contributions to Cortisol Responses in Infancy and Toddlerhood

The current study is one of the first prospective examinations of longitudinal associations between observed father caregiving behaviors and child cortisol reactivity and regulation in response to emotional arousal. Observations of father and mother caregiving behaviors and child cortisol levels in response to challenges at 7 months and 24 months of child age were collected. Analyses were based on a subsample of children from the Family Life Project who lived with both their biological mothers and fathers and for whom there was at least partial cortisol data (7 months: n = 717; 24 months: n = 579). At the challenge conducted at 7 months of child age, 49.0% of the sample were girls; racial composition of the sample was 25.8% African American and 74.2% European American. At the challenge conducted at 24 months of child age 49.9% of the sample were girls; racial composition was 24.7% African American and 75.3% European American. We conducted analyses across assessment points simultaneously using mixed linear modeling for repeated measures data to test for differential effects of fathering across infancy and toddlerhood. Concurrent measures of father negativity were positively associated with greater increases in child cortisol levels in response to emotion challenge at 7 months (p = .01) and with higher overall levels of cortisol at 24 months (p < .001). However, there was no evidence that father caregiving during infancy independently predicted later cortisol activity during toddlerhood.

Changes in maternal sensitivity across the first three years: are mothers from different attachment dyads differentially influenced by depressive symptomatology?

Hierarchical linear modeling was used to describe longitudinal relations between maternal sensitivity and depressive symptomatology for mothers of children with differing attachment classifications at 36 months of child age using data from the NICHD Study of Early Child Care. Attachment during toddlerhood was assessed using a modified Strange Situation Paradigm developed by the MacArthur Working Group on Attachment. On average, maternal sensitivity increased longitudinally from 6 to 36 months for groups with children classified as secure or resistant, but not for groups classified as avoidant or disorganized. Higher maternal depressive symptoms were associated with lower levels of sensitivity for all mothers, although this effect was significantly less severe for mothers of securely attached children. In addition, higher maternal depressive symptoms were associated with decreases in sensitivity from 6 to 36 months for mothers of children who at 36 months showed disorganized attachments combined with underlying patterns of avoidant or resistant behavior.

A biopsychosocial perspective on parenting and developmental psychopathology

Although considerable research has examined the relations between parental behavior and a range of child developmental outcomes, much of this work has been conducted at a very broad level of behavioral analysis. A developmental psychopathology framework and recent research conducted within this framework point to the need for models of parenting and child psychopathology that offer greater specificity regarding processes that may be implicated in the effects of these relationships. In addition, recent animal work and some human work has focused more on the proximal biological and social mechanisms through which parenting affects child outcomes. Our conceptualization of parenting effects acknowledges that family and child factors are embedded in a dynamic biological and social context that is key to understanding developmental trajectories of child adjustment. In this paper, we review two areas of research that are illuminating the biological processes underlying links between parenting and child psychopathology: molecular genetics and psychophysiology. We adopt a biopsychosocial perspective on developmental psychopathology that implies that a set of hierarchically organized, but reciprocally interacting, processes, from the genetic to the environmental, provide the essential elements of both normative and nonnormative development (Gottlieb, 2007). New directions stimulated by this general approach are discussed, with an emphasis on the contextual and developmental issues and applications implied by such a perspective.

Child Care and Cortisol across Early Childhood: Context Matters.

A considerable body of literature suggests that childrens child-care experiences may impact adrenocortical functioning in early childhood. Yet emerging findings also suggest that the magnitude and sometimes the direction of child-care effects on development may be markedly different for children from higher risk contexts. Using data from a large population-based sample of families from predominantly low-income backgrounds in rural communities, we tested the degree to which links between childrens child-care experiences (at 7-36 months) and their subsequent cortisol levels (at 48 months) were moderated by their level of cumulative environmental risk. Our results provided evidence of a crossover interaction between cumulative risk and child-care quantity. For children from low-risk contexts, greater weekly hours in child care were predictive of higher cortisol levels. In contrast, for children facing several cumulative risk factors, greater hours in child care per week were predictive of lower cortisol levels. These effects were robust after adjusting for several controls, including childrens cortisol levels in early infancy. Child-care quality and type were not predictive of childrens cortisol levels, and neither mitigated the conditional effect of child-care quantity on cortisol. These findings suggest that links between child care and childrens development may differ as a function of childrens broader ecologies.