Can Genetic Factors Explain the Spillover of Warmth and Negativity Across Family Relationships?

Parenting in the Context of the Child: Genetic and Social Processes

The focus on the role of parenting in child development has a long-standing history. When measures of parenting precede changes in child development, researchers typically infer a causal role of parenting practices and attitudes on child development. However, this research is usually conducted with parents raising their own biological offspring. Such research designs cannot account for the effects of genes that are common to parents and children, nor for genetically influenced traits in children that influence how they are parented and how parenting affects them. The aim of this monograph is to provide a clearer view of parenting by synthesizing findings from the Early Growth and Development Study (EGDS). EGDS is a longitudinal study of adopted children, their birth parents, and their rearing parents studied across infancy and childhood. Families (N = 561) were recruited in the United States through adoption agencies between 2000 and 2010. Data collection began when adoptees were 9 months old (males = 57.2%; White 54.5%, Black 13.2%, Hispanic/Latinx 13.4%, Multiracial 17.8%, other 1.1%). The median child age at adoption placement was 2 days (M = 5.58, SD = 11.32). Adoptive parents were predominantly in their 30s, White, and coming from upper-middle- or upper-class backgrounds with high educational attainment (a mode at 4-year college or graduate degree). Most adoptive parents were heterosexual couples, and were married at the beginning of the project. The birth parent sample was more racially and ethnically diverse, but the majority (70%) were White. At the beginning of the study, most birth mothers and fathers were in their 20s, with a mode of educational attainment at high school degree, and few of them were married. We have been following these family members over time, assessing their genetic influences, prenatal environment, rearing environment, and child development. Controlling for effects of genes common to parents and children, we confirmed some previously reported associations between parenting, parent psychopathology, and marital adjustment in relation to child problematic and prosocial behavior. We also observed effects of children's heritable characteristics, characteristics thought to be transmitted from parent to child by genetic means, on their parents and how those effects contributed to subsequent child development. For example, we found that genetically influenced child impulsivity and social withdrawal both elicited harsh parenting, whereas a genetically influenced sunny disposition elicited parental warmth. We found numerous instances of children's genetically influenced characteristics that enhanced positive parental influences on child development or that protected them from harsh parenting. Integrating our findings, we propose a new, genetically informed process model of parenting. We posit that parents implicitly or explicitly detect genetically influenced liabilities and assets in their children. We also suggest future research into factors such as marital adjustment, that favor parents responding with appropriate protection or enhancement. Our findings illustrate a productive use of genetic information in prevention research: helping parents respond effectively to a profile of child strengths and challenges rather than using genetic information simply to identify some children unresponsive to current preventive interventions.

Utilising Genetically-Informed Research Designs to Better Understand Family Processes and Child Development: Implications for Adoption and Foster Care Focused Interventions

Understanding the interplay between genetic factors and family environmental processes (e.g., inter-parental relationship quality, positive versus negative parenting practices) and children's mental health (e.g., anxiety, depression, conduct problems, ADHD) in the contexts of adoption and foster-care research and practice is critical for effective prevention and intervention programme development. Whilst evidence highlights the importance of family environmental processes for the mental health and well-being of children in adoption and foster care, there is relatively limited evidence of effective interventions specifically for these families. Additionally, family-based interventions not specific to the context of adoption and foster-care typically show small to medium effects, and even where interventions are efficacious, not all children benefit. One explanation for why interventions may not work well for some is that responses to intervention may be influenced by an individual's genetic make-up. This paper summarises how genetically-informed research designs can help disentangle genetic from environmental processes underlying psychopathology outcomes for children, and how this evidence can provide improved insights into the development of more effective preventative intervention targets for adoption and foster-care families. We discuss current difficulties in translating behavioural genetics research to prevention science, and provide recommendations to bridge the gap between behavioural genetics research and prevention science, with lessons for adoption and foster-care research and practice.

Disentangling Child-Specific and Family-Wide Processes Underlying Negative Mother-Child Transactions

The current study examines the transactional processes between maternal negativity and child disruptive behavior during early childhood, using a sibling comparison design. This design allows for a more sophisticated test of the behavioral training hypothesis than is possible when only one child per family is included in the analysis as it excludes two confounders (passive gene-environment correlation and family-wide environmental influence). Three hundred and ninety-seven families were visited on three occasions when the target child was 1.5, 3 and 4.5 years old (920 children, 51.5% female). The target child and up to three older siblings per family were included in data collection and analysis. Mothers and fathers reported on children's disruptive behavior and mothers reported on their negativity to children. Within-family cross-lag pathways, as well as a significant indirect effect through which children increased their own disruptive behavior via maternal negativity confirmed a behavioral training effect. Family level maternal negativity and sibling disruptive behavior showed high levels of stability over three to four years and no context effect for maternal negativity or sibling disruptive behavior was seen. The theoretical and clinical implications of these findings are discussed.

Risk effects of high and low relative humidity on allergic rhinitis: Time series study

BACKGROUND

The relationship between environmental factors and allergic rhinitis (AR) has become a focal point recently. However, few studies have investigated the adverse effects of both high relative humidity (RH) and low relative humidity. Moreover, the laged effect and disease burden of RH on AR were also neglected.

OBJECTIVES

To explore the association of both high and low RH on daily AR hospital outpatients, and to quantify the corresponding disease burden attributable to RH.

METHODS

In our study, we define 95th as high RH and 5th as low RH. A distributed lag non-linear model (DLNM) combined with a Poisson generalized linear regression model were applied to analyze the relationship between RH and hospital outpatients for AR. All patients were retrieved from Anhui Provincial Children's Hospital (n = 37,221) from January 2015 to December 2016. Daily meteorological and air pollutant data were collected by Hefei Meteorological Bureau and Environmental Protection Agency. Subgroup analyses were conducted by gender and occupational groups.

RESULTS

Acute adverse effects of high and low RH on AR were explored respectively, with an increase of daily AR outpatients when encountered high and low RH. The low RH presented a risk effect at current day and lasted up to the eighth day. However, high RH began to appear a risk effect on the fourth day. Notably, the fraction of hospital outpatients attributable to low RH was 5.22% (95% CI: 1.92%, 8.33%) and high RH was 4.07% (95% CI: 1.13%, 7.30%) in the backward perspective. Additionally, male and students apparent to be more sensitive to the effects of low RH.

CONCLUSION

This study suggests that both high and low RH are potential trigger for AR hospital outpatients in Hefei, China. Our studies might offer valuable messages to health practitioners and useful direction to decisions-makers respectively.

Parenting Stress, Mental Health, Dyadic Adjustment: A Structural Equation Model

Objective: In the 1st year of the post-partum period, parenting stress, mental health, and dyadic adjustment are important for the wellbeing of both parents and the child. However, there are few studies that analyze the relationship among these three dimensions. The aim of this study is to investigate the relationships between parenting stress, mental health (depressive and anxiety symptoms), and dyadic adjustment among first-time parents.

Method: We studied 268 parents (134 couples) of healthy babies. At 12 months post-partum, both parents filled out, in a counterbalanced order, the Parenting Stress Index-Short Form, the Edinburgh Post-natal Depression Scale, the State-Trait Anxiety Inventory, and the Dyadic Adjustment Scale. Structural equation modeling was used to analyze the potential mediating effects of mental health on the relationship between parenting stress and dyadic adjustment.

Results: Results showed the full mediation effect of mental health between parenting stress and dyadic adjustment. A multi-group analysis further found that the paths did not differ across mothers and fathers.

Discussion: The results suggest that mental health is an important dimension that mediates the relationship between parenting stress and dyadic adjustment in the transition to parenthood.

The Maternal Emotional Climate Predicts Twin Sibling Relationship Quality

We investigated the association between maternal expressed emotion and twin relationship quality, after controlling for a maternal questionnaire measure of the mother-child relationship. This was explored within a community sample of 156 mothers and their two young twin children (M child age = 3.69 years; SD child age = 0.37). Mothers reported on the twin-twin relationship and the mother-child relationship via questionnaire. They were also interviewed about each child using the innovative Preschool Five Minute Speech Sample (Daley et al., 2003), which yields information about relative positive:negative maternal expressed emotion. Mothers who expressed more family-wide positive emotion and less family-wide negative emotion also reported more positivity, but not negativity, within the twin relationship - even when controlling for questionnaire reports of the mother-child relationship. Counter to expectations, discrepancies in mothers' expressed emotion between their twins also predicted more positive sibling relationships. Our findings corroborate the well established spill-over effect, whereby families are viewed as emotional units of interdependent individuals, none of whom can be understood in isolation from one another. Most importantly, the Preschool Five Minute Speech Sample provides information about mothering that questionnaire reports may not, and thus it is a useful tool in better understanding the twin family system.

Parental Relationship with Twins from Pregnancy to 3 Months: The Relation Among Parenting Stress, Infant Temperament, and Well-Being

Objective: The transition to parenthood, from pregnancy to postpartum period, is a critical process, particularly for couples expecting twins. There is very little literature regarding the links between anxiety, depression, dyadic adjustment, parental stress, and infant temperament spanning from pregnancy to postpartum. This study has two aims: first, to examine whether mothers' and fathers' anxiety, depression, and dyadic adjustment, assessed at the sixth month of pregnancy and 3 months postpartum, are associated with infants' negative affectivity (NA) and parenting stress; second, to examine whether there is any difference between fathers' and mothers' levels of parenting stress and perception of the twins' temperament, as well as to evaluate, separately for mothers and fathers, whether the levels of parenting stress and perception of child temperament differ for each twin. Method: The study participants were 58 parents (29 couples) and their healthy 58 twin babies (51.7% boys, 48.3% girls). Mothers' ages ranged from 30 to 44 years, (MAge = 36.3 years, SD = 3.2 years), and fathers' ages ranged from 32 to 52 years, (MAge = 38.2 years, SD = 4.4 years). The parents, during the pregnancy period and 3 months after delivery, filled out the Edinburgh Postnatal Depression Scale, the State-Trait Anxiety Inventory, and the Dyadic Adjustment Scale. Three months after delivery they also filled out the Parenting Stress Index-Short Form and the Infant Behavior Questionnaire Revised. Results: The analyses showed a significant correlation between parental anxiety/depression symptoms and infants' NA and parenting stress (in both mothers and fathers). Moreover, compared to fathers, mothers reported higher scores on specific dimensions of the infants' NA, [t(28) = -2.62 and p < 0.05; t(28) = 2.09 and p < 0.05], and parenting stress, [t(28) = 2.19 and p < 0.05; t(28) = 2.23 and p < 0.05], but only for Twin 2. Finally, the results showed that mothers' perceptions of child temperament vary between two twins, [e.g., distress to limitations: t(28) = 2.08 and p < 0.05]. Discussion: This study highlights the peculiarity of twin parenthood during the fourth trimester. In particular, the differences between twins' mothers' and fathers' perceptions are relevant from a clinical perspective and for perinatal professionals. It would be interesting to study the long-term impact of mothers' and fathers' differing perceptions of their twins.

Refining Intervention Targets in Family-Based Research: Lessons From Quantitative Behavioral Genetics

The results from a large body of family-based research studies indicate that modifying the environment (specifically dimensions of the social environment) through intervention is an effective mechanism for achieving positive outcomes. Parallel to this work is a growing body of evidence from genetically informed studies indicating that social environmental factors are central to enhancing or offsetting genetic influences. Increased precision in the understanding of the role of the social environment in offsetting genetic risk might provide new information about environmental mechanisms that could be applied to prevention science. However, at present, the multifaceted conceptualization of the environment in prevention science is mismatched with the more limited measurement of the environment in many genetically informed studies. In this article, we present a framework for translating quantitative behavioral genetic research to inform the development of preventive interventions. The measurement of environmental indices amenable to modification is discussed within the context of quantitative behavioral genetic studies. In particular, emphasis is placed on the necessary elements that lead to benefits in prevention science, specifically the development of evidence-based interventions. We provide an example from an ongoing prospective adoption study to illustrate the potential of this translational process to inform the selection of preventive intervention targets.

Angry responses to infant challenges: parent, marital, and child genetic factors associated with harsh parenting

This study examined genetic and environmental influences on harsh parenting of adopted 9-month-olds (N = 503), with an emphasis on positive child-, parent-, and family-level characteristics. Evocative gene-environment correlation (rGE) was examined by testing the effect of both positive and negative indices of birth parent temperament on adoptive parents' harsh parenting. Adoptive fathers' harsh parenting was inversely related to birth mother positive temperament, indicating evocative rGE, as well as to marital quality. Adoptive parents' negative temperamental characteristics were related to hostile parenting for both fathers and mothers. Findings support the importance of enhancing positive family characteristics in addition to mitigating negative characteristics, as well as engaging multiple levels of the family system to prevent harsh parenting.

Marital adjustment as a moderator for genetic and environmental influences on parenting

Family systems theory proposes that the parent-child relationship is embedded within the broader system of the family, and that other family subsystems can influence the dynamics and quality of the parent-child relationship. The current paper examines marital adjustment as a context for the parent-child relationship during adolescence. Specifically, the extent to which marital adjustment moderates child-based genetic and environmental effects on the parent-child relationship was assessed. Data for this study were from the initial wave of the Nonshared Environment in Adolescent Development (NEAD) study, and included 720 families with same-sex sibling pairs, ages 10-18 years. A range of sibling and family types was sampled, with 93 monozygotic twin pairs, 99 dizygotic twin pairs, and 95 sibling pairs from nondivorced families, and 182 sibling, 109 half-sibling, and 130 unrelated sibling pairs from stepfamilies. Composite measures of marriage (based on parent reports) and parenting (based child and parent reports and observation ratings) were examined. Results indicate that as marital adjustment declines, evocative child effects on parenting increase, while the role of shared family experiences declines. However, the specific impact of marital adjustment on child-based genetic and child-specific nonshared environmental contributions to parenting differed for mothers and fathers. This study identifies a previously unexplored mechanism through which family subsystems influence each other.

Current parental depression and offspring perceived self-competence: a quasi-experimental examination

A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52 %) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-competence was measured using a modified Harter Perceived Competence Scale. Cousin comparisons and Children of Twins designs suggested that associations between maternal depressive symptoms and offspring perceived self-competence were due to shared genetic/environmental liability. The mechanism responsible for father-offspring associations, however, was independent of genetic factors and of extended family environmental factors, supporting a causal inference. Thus, mothers and fathers may impact offspring perceived self-competence via different mechanisms and unmeasured genetic and environmental selection factors must be considered when studying the intergenerational transmission of cognitive vulnerabilities for depression.

A genetically informed study of associations between family functioning and child psychosocial adjustment

Research has documented associations between family functioning and offspring psychosocial adjustment, but questions remain regarding whether these associations are partly due to confounding genetic factors and other environmental factors. The current study used a genetically informed approach, the Children of Twins design, to explore the associations between family functioning (family conflict, marital quality, and agreement about parenting) and offspring psychopathology. Participants were 867 twin pairs (388 monozygotic; 479 dizygotic) from the Twin and Offspring Study in Sweden, their spouses, and children (51.7% female; M = 15.75 years). The results suggested associations between exposure to family conflict (assessed by the mother, father, and child) and child adjustment were independent of genetic factors and other environmental factors. However, when family conflict was assessed using only children's reports, the results indicated that genetic factors also influenced these associations. In addition, the analyses indicated that exposure to low marital quality and agreement about parenting was associated with children's internalizing and externalizing problems and that genetic factors also contributed to the associations of marital quality and agreement about parenting with offspring externalizing problems.

The role of aggressive personality and family relationships in explaining family conflict

This study investigated whether genetic and environmental influences on global family conflict are explained by parents' personality, marital quality, and negative parenting. The sample comprised 876 same-sex pairs of twins, their spouses, and one adolescent child per twin from the Twin and Offspring Study in Sweden. Genetic influences on aggressive personality were correlated with genetic influences on global family conflict. Nonshared environmental influences on marital quality and negative parenting were correlated with nonshared environmental influences on global family conflict. Results suggest that parents' personality and unique experiences within their family relationships are important for understanding genetic and environmental influences on global conflict in the home.

Intended sensitive and harsh caregiving responses to infant crying: the role of cry pitch and perceived urgency in an adult twin sample

OBJECTIVE

To examine the underlying mechanisms of adults' intended caregiving responses to cry sounds in a behavioral genetic design and to investigate the role of cry pitch and perceived urgency in sensitive and harsh caregiving responses.

METHODS

The sample consisted of 184 adult twin pairs (18-69 years), including males and females, parents and nonparents. In an experimental design we presented cry sounds varying in pitch and measured adults' perception and their intended caregiving responses. Cry stimuli were based on a 10-second cry sample of a 2-day-old infant with a fundamental frequency averaging 500 Hz. Two additional cry sounds were created by digitally increasing the fundamental frequency to 700 and 900 Hz.

RESULTS

Individual differences in the perceived urgency of infant crying and intended sensitive caregiving responses were explained by genetic factors (38% and 39%, respectively), while the variance in harsh caregiving responses was due to shared (31%) and unique (69%) environmental influences. Adults were more likely to indicate sensitive caregiving responses to higher-pitched cry sounds and when they perceived the cries as more urgent, while high-pitched cry sounds were also directly associated with harsh caregiving responses.

CONCLUSIONS

The influence of genetic factors on intended caregiving responses to infant crying is substantial for normal variations in sensitive caregiving, but absent for harsh caregiving responses. The findings suggest that the perception of infant crying as urgent paves the way for more immediate and affectionate caregiving responses, while an extreme increase in cry pitch may present a direct risk factor for more irritated, negative and even harsh parenting.

PRACTICE IMPLICATIONS

Infants who display abnormal cry acoustics such as extreme increases in pitch may be at risk for harsh parenting. Interventions should promote parental sensitive response to distress vocalizations to prevent harsh parenting in case of at-risk infants.