Erica L. Spotts

Genetic variation in the vasopressin receptor 1a gene (AVPR1A) associates with pair-bonding behavior in humans

Pair-bonding has been suggested to be a critical factor in the evolutionary development of the social brain. The brain neuropeptide arginine vasopressin (AVP) exerts an important influence on pair-bonding behavior in voles. There is a strong association between a polymorphic repeat sequence in the 5′ flanking region of the gene (avpr1a) encoding one of the AVP receptor subtypes (V1aR), and proneness for monogamous behavior in males of this species. It is not yet known whether similar mechanisms are important also for human pair-bonding. Here, we report an association between one of the human AVPR1A repeat polymorphisms (RS3) and traits reflecting pair-bonding behavior in men, including partner bonding, perceived marital problems, and marital status, and show that the RS3 genotype of the males also affects marital quality as perceived by their spouses. These results suggest an association between a single gene and pair-bonding behavior in humans, and indicate that the well characterized influence of AVP on pair-bonding in voles may be of relevance also for humans.

Genetic and Environmental Influences on Mothering of Adolescents: A Comparison of Two Samples

This study examined 2 samples of adolescents and mothers using a child-based design (Nonshared Environment in Adolescent Development [NEAD] project, N = 395 families) and a parent-based design (Twin Moms [TM] project, N = 236 twin family pairs) to compare genetic and environmental influences on mothering. For both samples, the same measures of positivity, negativity, control, and monitoring were used. The use of matched child-based and parent-based samples enabled passive and nonpassive genotype-environment (GE) correlations to be approximated, providing information about process. Passive GE correlations were suggested for mothers positivity and monitoring. For mothers negativity and control, primarily nonpassive GE correlations were suggested. In several cases, both types of GE correlation were indicated. Finally, observer ratings of negativity and monitoring were influenced only by environmental factors.

Variation in the Oxytocin Receptor Gene Is Associated with Pair-Bonding and Social Behavior

BACKGROUND In specific vole and primate species the neuropeptide oxytocin plays a central role in the regulation of pair-bonding behavior. Here we investigate the extent to which genetic variants in the oxytocin receptor gene (OXTR) are associated with pair-bonding and related social behaviors in humans. METHODS We first genotyped twelve single nucleotide polymorphisms (SNPs) in the TOSS (Twin and Offspring Study in Sweden) (n = 2309) and the TCHAD (Swedish Twin Study of Child and Adolescent Development) (n = 1240), comprising measures of self-reported pair-bonding behavior. In the TOSS sample we further investigated one of the SNPs for measures of marital status and quality. Moreover, in the TCHAD sample we explored the longitudinal relationship between precursors of pair-bonding during childhood and subsequent behavior in romantic relationships. Finally, in the TCHAD study and in the Child and Adolescent Twin Study of Sweden (CATSS) (n = 1771), the association between the same SNP and childhood behaviors was investigated. RESULTS One SNP (rs7632287) in OXTR was associated with traits reflecting pair-bonding in women in the TOSS and TCHAD samples. In girls the rs7632287 SNP was further associated with childhood social problems, which longitudinally predicted pair-bonding behavior in the TCHAD sample. This association was replicated in the CATSS sample in which an association between the same SNP and social interaction deficit symptoms from the autism spectrum was detected. CONCLUSION These results suggest an association between variation in OXTR and human pair-bonding and other social behaviors, possibly indicating that the well-described influence of oxytocin on affiliative behavior in voles could also be of importance for humans.

Father-adolescent relationships and the role of genotype-environment correlation.

This study uses 2 samples of adolescents and parents--the child-based Nonshared Environment in Adolescent Development project (NEAD; D. Reiss, J. M. Neiderhiser, E. Hetherington, & R. Plomin, 2000; N = 395 families) and the parent-based Twin and Offspring Study in Sweden (TOSS; N = 909 twin family pairs)--to investigate passive and evocative genotype-environment correlation (rGE) on fathering. Both samples used the same measures of positivity, negativity, control, and monitoring. A previous report examining mothering found evidence for passive rGE for positivity and monitoring, and evocative rGE for negativity and control, although both types of rGE were suggested in many cases. The current report focuses on fathering. Father reports of positivity and control are influenced by evocative rGE, whereas father reports of negativity and monitoring are influenced by both passive and evocative rGE. Adolescent reports of fathers positivity and negativity were influenced by both evocative and passive rGE, and control and monitoring by passive rGE. The most notable difference in findings for fathers and mothers is for positivity and the presence of rGE for fathers control and monitoring. These findings and their implications are discussed.

The Intergenerational Transmission of Anxiety: A Children-of-Twins Study

OBJECTIVE The transmission of anxiety within families is well recognized, but the underlying processes are poorly understood. Twin studies of adolescent anxiety demonstrate both genetic and environmental influence, and multiple aspects of parenting are associated with offspring anxiety. To date, the children-of-twins design has not been used to evaluate the relative contributions of genetic transmission compared with direct transmission of anxiety from parents to their offspring. METHOD Anxiety and neuroticism measures were completed by 385 monozygotic and 486 dizygotic same-sex twin families (37% male twin pair families) from the Twin and Offspring Study in Sweden. Structural equation models tested for the presence of both genetic and environmental transmission from one generation to the next. RESULTS For both anxiety and neuroticism, the models provide support for significant direct environmental transmission from parents to their adolescent offspring. In contrast, there was no evidence of significant genetic transmission. CONCLUSIONS The association between parental and offspring anxiety largely arises because of a direct association between parents and their children independent of genetic confounds. The lack of genetic transmission may reflect there being different genetic effects on these traits in adolescence and adulthood. Direct environmental transmission is in line with developmental theories of anxiety suggesting that children and adolescents learn anxious behaviors from their parents through a number of pathways such as modeling. Future analyses should combine children-of-twins data with child twin data in order to examine whether this direct effect solely represents parental influences on the offspring or whether it also includes child/adolescent anxiety evoking parental anxiety.

Genetic and environmental influences on teacher ratings of the Child Behavior Checklist

The knowledge we have of childhood and adolescent behaviour is, to some extent, a function of the unique perspective of the rater. Although many behavioural genetics studies have used parent and child self-reports in their assessments of child and adolescent adjustment, few have included teacher ratings of behaviour. It is possible that genetic and environmental contributions to teacher reports are different from those using parent and self-reports. The present study examined genetic and environmental influences on six subscales of the Child Behavior Checklist Teacher Report Form (CBC-TRF) using a normative sample of adolescents. The sample consisted of 373 same-sex twin and sibling pairs of varying degrees of genetic relatedness participating in the Nonshared Environment in Adolescent project (NEAD). For all of the CBC subscales, except attention problems and social problems, nonshared environmental influence was the most important source of variance. Additive genetic factors were of moderate importance for externalising behaviours, whereas nonadditive genetic factors contributed to the anxious/depressed, attention problems, withdrawn, and social problems subscales. For none of the constructs was shared environment a significant influence. Three alternative models testing for contrast effects, differences in twin and nontwin siblings, and differences in nondivorced and stepfamilies were examined. In most cases, the best-fitting model was a model that did not include any of these effects, suggesting that these factors do not critically affect the basic model. However, some of the patterns of correlations and parameter estimates were unusual and may warrant future investigation.

Genetic Effects on Women's Positive Mental Health: Do Marital Relationships and Social Support Matter?

Interpersonal relationships are important factors in mental health. A genetically sensitive design was used to examine associations among marital quality, adequacy of social support, and 2 aspects of positive mental health in a sample of 652 Swedish twin women and their families. There were 3 main findings. First, the covariance between relationships and positive mental health was partially accounted for by common genetic variance. Second, nonshared environmental influences played a substantial role in the covariance among the 3 constructs, with evidence for husbands being a source of this influence. Finally, different patterns of associations were found between relationships and 2 aspects of mental health, well-being and global self-worth, which shows how seemingly similar constructs can be differentially associated with relationships. Together, these findings emphasize the importance of genetically informed studies in family research and the role of the environment and interpersonal relationships in promoting and improving mental health.

Examining the Origins of Gender Differences in Marital Quality: A Behavior Genetic Analysis

Numerous researchers have examined gender differences in marital quality, with mixed results. In this study, the authors further this investigation by looking for genetic and environmental sources of variation in marital quality. The 1st aim of the study was to replicate previous findings of genetic and nonshared environmental influences on marital quality. The 2nd was to explore the etiology of gender differences in marital quality. The Virginia Adult Twin Study of Psychiatric and Substance Use Disorders sample of twin men and twin women was used. Genetic and nonshared environmental factors were again found to influence marital quality. Findings also suggest small differences between men and women in the levels of genetic and environmental influence on variance in marital quality. The mens reports of marital warmth and conflict were influenced by the same genetic factors, but womens reports of marital warmth and conflict were influenced by different genetic factors. Results are discussed in the context of previous research on social support and implications for future studies of the etiology of marital quality.

The relationship between parental depressive symptoms and offspring psychopathology: Evidence from a children-of-twins study and an adoption study

Background Parental depressive symptoms are associated with emotional and behavioural problems in offspring. However, genetically informative studies are needed to distinguish potential causal effects from genetic confounds, and longitudinal studies are required to distinguish parent-to-child effects from child-to-parent effects. Method We conducted cross-sectional analyses on a sample of Swedish twins and their adolescent offspring (n = 876 twin families), and longitudinal analyses on a US sample of children adopted at birth, their adoptive parents, and their birth mothers (n = 361 adoptive families). Depressive symptoms were measured in parents, and externalizing and internalizing problems measured in offspring. Structural equation models were fitted to the data. Results Results of model fitting suggest that associations between parental depressive symptoms and offspring internalizing and externalizing problems remain after accounting for genes shared between parent and child. Genetic transmission was not evident in the twin study but was evident in the adoption study. In the longitudinal adoption study child-to-parent effects were evident. Conclusions We interpret the results as demonstrating that associations between parental depressive symptoms and offspring emotional and behavioural problems are not solely attributable to shared genes, and that bidirectional effects may be present in intergenerational associations.

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 childrens 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 childrens internalizing and externalizing problems and that genetic factors also contributed to the associations of marital quality and agreement about parenting with offspring externalizing problems.