Implicit association to infant faces: Genetics, early care experiences, and cultural factors influence caregiving propensities

Functional near-infrared spectroscopy is a useful tool for multi-perspective psychobiological study of neurophysiological correlates of parenting behaviour

The quality of the relationship between caregiver and child has long-term effects on the cognitive and socio-emotional development of children. A process involved in human parenting is the bio-behavioural synchrony that occurs between the partners in the relationship during interaction. Through interaction, bio-behavioural synchronicity allows the adaptation of the physiological systems of the parent to those of the child and promotes the positive development and modelling of the child's social brain. The role of bio-behavioural synchrony in building social bonds could be investigated using functional near-infrared spectroscopy (fNIRS). In this paper we have (a) highlighted the importance of the quality of the caregiver-child relationship for the child's cognitive and socio-emotional development, as well as the relevance of infantile stimuli in the activation of parenting behaviour; (b) discussed the tools used in the study of the neurophysiological substrates of the parental response; (c) proposed fNIRS as a particularly suitable tool for the study of parental responses; and (d) underlined the need for a multi-systemic psychobiological approach to understand the mechanisms that regulate caregiver-child interactions and their bio-behavioural synchrony. We propose to adopt a multi-system psychobiological approach to the study of parental behaviour and social interaction.

Gene-Environment Interactions in Face Categorization: Oxytocin Receptor Genotype x Childcare Experience Shortens Reaction Time

Human faces capture attention, provide information about group belonging, and elicit automatic prepared responses. Early experiences with other-race faces play a critical role in acquiring face expertise, but the exact mechanism through which early experience exerts its influence is still to be elucidated. Genetic factors and a multi-ethnic context are likely involved, but their specific influences have not been explored. This study investigated how oxytocin receptor gene (OXTR) genotypes and childcare experience interacted to regulate face categorization in adults. Information about single nucleotide polymorphisms of OXTR (rs53576) and experiences with own- and other-race child caregivers was collected from 89 Singaporean adults, who completed a visual categorization task with own- versus other-race faces. Participants were grouped into A/A homozygotes and G carriers and assigned a score to account for their type of child caregiver experience. A multivariate linear regression model was used to estimate the effect of genetic group, child caregiver experience, and their interaction on categorization reaction time. A significant interaction of genetic group and child caregiver experience (t = 2.48, p = 0.015), as well as main effects of both genetic group (t = −2.17, p = 0.033) and child caregiver experience (t = −4.29, p < 0.001) emerged. Post-hoc analysis revealed that the correlation between categorization reaction time and child caregiver experience was significantly different between the two genetic groups. A significant gene x environment interaction on face categorization appears to represent an indirect pathway through which genes and experiences interact to shape mature social sensitivity to faces in human adults.

Serotonin Transporter Gene Polymorphisms and Maternal Overprotection Regulate Adult Social Expectations on Close Relationships

Humans are evolutionary-driven to adult mating and conceive social expectations on the quality of their affiliations. The genetic susceptibility to adverse environments in critical periods can alter close relationships. The current research investigates how the promoter region of the Serotonin Transporter Gene (5-HTTLPR) and perceived caregiving behavior in childhood could influence the social expectations on close adult relationships. For this purpose, 5-HTTLPR data was collected from the buccal mucosa of 65 Italian individuals (33 males). The participants filled (a) the Parental Bonding Instrument (PBI) to provide the levels of care and overprotection from mother and father, and (b) the Experience in Close Relationships-Revised (ECR-R) to report the social expectations on the intimate relationship assessed in terms of anxiety and avoidance from the partner. An interaction effect between 5-HTTLPR and PBI dimensions on the ECR-R scores was hypothesized. Results confirmed that the interplay between the genetic groups and history of maternal overprotection predicted avoidance experienced in romantic relationships in adulthood. Moreover, both adult anxiety and avoidance felt in an intimate relationship were found to covary as a function of maternal overprotection. The present work proposes further evidence of the genetic and parental mechanisms regulating social expectations involved in close relationships.

Recalled Parental Bonding Interacts with Oxytocin Receptor Gene Polymorphism in Modulating Anxiety and Avoidance in Adult Relationships

Early interactions with significant individuals affect social experience throughout the course of a lifetime, as a repeated and prolonged perception of different levels of care, independence, or control influences the modulation of emotional regulatory processes. As many factors play a role in shaping the expectations and features of social interaction, in this study, we considered the influence of parental bonding and genetic allelic variation of oxytocin receptor gene polymorphism (rs53576) over levels of experienced anxiety and avoidance in 313 young adults belonging to two different cultural contexts, namely Italy and Singapore. Results highlighted a major effect of maternal characteristics, care, and overprotection, with differences between the two cultural groups. Additionally, the interaction between rs53576 and maternal overprotection suggested different environmental susceptibility in the Italian sample and the Singaporean one. Implications for clinical work and future steps are described in the Conclusion.

Dopaminergic and neurotrophic genetic polymorphisms modulate the implicit gender-science stereotype

Genetic approaches to both the gender-science stereotype and implicit social cognition have received increasing attention in recent years. We explored whether single nucleotide polymorphisms (SNPs) in dopaminergic and neurotrophic systems (i.e., COMT, BDNF genotypes) explain variations in the implicit gender-science stereotype. We genotyped 413 adolescents and assessed their implicit gender-science stereotype with the Implicit Association Test. Replication on a subsample (N = 312) was conducted 2 years later. Results showed that SNP-level variations within the COMT and BDNF genes were consistently associated with the implicit gender-science stereotype in both investigations. These findings suggest that variants in the COMT and BDNF genes may contribute to the variation of implicit gender-science stereotype.

How stress can influence brain adaptations to motherhood

Research shows that a woman's brain and body undergo drastic changes to support her transition to parenthood during the perinatal period. The presence of this plasticity suggests that mothers' brains may be changed by their experiences. Exposure to severe stress may disrupt adaptive changes in the maternal brain and further impact the neural circuits of stress regulation and maternal motivation. Emerging literature of human mothers provides evidence that stressful experience, whether from the past or present environment, is associated with altered responses to infant cues in brain circuits that support maternal motivation, emotion regulation, and empathy. Interventions that reduce stress levels in mothers may reverse the negative impact of stress exposure on the maternal brain. Finally, outstanding questions regarding the timing, chronicity, types, and severity of stress exposure, as well as study design to identify the causal impact of stress, and the role of race/ethnicity are discussed.

Non-Suicidal Self-Injury Among Italian Adolescents: The Role of Parental Rejection, Self-Concept, Anger Expression, and Body Investment

Objective

Parental rejection, poor self-concept, anger expression, and negative body investment have often been associated with non-suicidal self-injury (NSSI). However, research has investigated each factor separately. To address this shortcoming, the main aim of the study was to integrate these factors and test a hierarchical regression to examine the impact of each factor above and beyond the others.

Method

A cross-sectional sample of 481 Italian high school students aged 13-19 (M_age=15.48; SD=1.46) were screened by self-report measures that assess parental rejection, self-concept, anger expression, body emotional investment, and NSSI. A semi-structured interview was administered in order to assess the characteristics of self-injurious behaviors.

Results

After the interview, twenty-three (4.8%) students reported having engaged in NSSI (Mage =12.63; SD=1.58). Neither gender nor age differences were found. The hierarchical regression revealed the NSSI was associated with the inward expression of anger (ORs=1.1–1.7) and the negative body investment (ORs=.037–.281).

Conclusions

These findings point out that the expression of anger inwardly and the emotional investment in the body may be salient factors to consider in understanding the occurrence of NSSI among adolescents. The clinical relevance of these findings was discussed.

Oxytocin receptor gene and parental bonding modulate prefrontal responses to cries: a NIRS Study

The ability to interpret and regulate emotions relies on experiences of emotional socialization, obtained firstly through the interaction with the parents, and on genetic features that affect how individuals take on social situations. Evidence from the genetic field states that specific allelic variations of the oxytocin receptor gene polymorphisms regulate physiological modulation of human behavior, especially concerning responses to social cues and affiliative behaviors. Starting from this gene-by-environment interaction frame, we assessed 102 young adults for OXTr rs53576 and rs2254298, recalled parental bonding (using the Parental Bonding Instrument), and recorded participants' neural responses to social stressors using Near InfraRed Spectroscopy (NIRS). The results highlight that higher genetic susceptibility (G/G homozygous) to familiar context and positive early life interactions modulate more optimal neural responses to general social cues, in terms of promptness to action. With regards to the dimensions of parental bonding, we found lateralized effects, with greater activation in the right prefrontal cortex for Care subscales, and on the left side of the prefrontal cortex for Overprotection. Results provide evidence to understand the neurological mechanisms behind the negative impact of poor parenting practices on the child.

The importance of attachment in infant and influencing factors

Attachment is a pattern of interaction and communication established and developed between mother and baby. For the growth of mentally and physically healthy individuals, the mother is expected to create a suitable attachment starting before the birth and to maintain it afterwards. It is also necessary for the baby to establish appropriate and safe attachment towards the mother in a similar manner. There are several factors that affect the attachment. Also, some studies show that children with attachment problems also have problems in their future lives. Healthcare professionals need to be aware of these factors and evaluate the child in terms of healthy parental communication and child development in well-child visits. As a result of these evaluations, multidisciplinary approaches to the mother-child pair can be established and the child’s health is protected mentally and physically for healthy generations.

Implicit associations to infant cry: Genetics and early care experiences influence caregiving propensities

Adults' sensitive appraisal of and response to infant cry play a foundational role in child development. Employing a gene × environment (G × E) approach, this study investigated the interaction of genetic polymorphisms of the serotonin transporter gene (5-HTTLPR) and oxytocin receptor genes (OXTR; rs53576, rs2254298) with early parental care experiences in influencing adults' implicit associations to infant cry. Eighty nulliparous adults (40 females, 40 males) responded to the Parental Acceptance-Rejection Questionnaire (PARQ), a measure of early care experiences, and participated in a Single Category Implicit Association Task (SC-IAT) to measure implicit associations to infant cry. Independent of parental experience, the valence of the implicit response to infant cry is associated with the serotonin transporter gene polymorphism (5-HTTLPR), with LL-carriers showing more positive implicit associations than S-carriers. OXTR rs53576 moderated the relation between parental rejection and implicit appraisal of infant cry: A-carriers who experienced negative early care showed an implicit positive appraisal of infant cry, whereas in GG carriers, positive early care experiences were associated with an implicit positive reaction to infant cry. OXTR rs2254298 had no relation to implicit associations to infant cry or to early care experiences. These findings cast light on the possible interplay of genetic inheritance and early environment in influencing adults' responses to infant cry that may be incorporated into screening protocols aimed at identifying at-risk adult-infant interactions.

Gene × Environment Interaction in Developmental Disorders: Where Do We Stand and What's Next?

Although the field of psychiatry has witnessed the proliferation of studies on Gene × Environment (G×E) interactions, still limited is the knowledge we possess of G×E interactions regarding developmental disorders. In this perspective paper, we discuss why G×E interaction studies are needed to broaden our knowledge of developmental disorders. We also discuss the different roles of hazardous versus self-generated environmental factors and how these types of factors may differentially engage with an individual's genetic background in predicting a resulting phenotype. Then, we present examplar studies that highlight the role of G×E in predicting atypical developmental trajectories as well as provide insight regarding treatment outcomes. Supported by these examples, we explore the need to move beyond merely examining statistical interactions between genes and the environment, and the motivation to investigate specific genetic susceptibility and environmental contexts that drive developmental disorders. We propose that further parsing of genetic and environmental components is required to fully understand the unique contribution of each factor to the etiology of developmental disorders. Finally, with a greater appreciation of the complexities of G×E interaction, this discussion will converge upon the potential implications for clinical and translational research.

Ethnic effects when facing children: An ERP study

Abundant research has highlighted a disadvantage experienced by children of ethnic minority groups in, for example, educational and health care settings. In order to understand implicit attitudes that contribute to ethnic disparities, underlying neural correlates have been widely studied. However, this has been limited to the context of adults. Using a sample of nulliparous Caucasian females (N = 46), the current study is the first to examine how early attentional and facial perceptual processing stages, assessed with event-related brain potentials (ERPs), differentiate for stimuli of young ingroup (of the same ethnicity) or outgroup (of a different ethnicity) children. Additionally, we assessed how a differentiation in ERPs may relate to subsequent adult responsiveness to children by measuring both cuteness ratings and motivation to view child faces. Similar to previous findings for adult facial stimuli, we found significant differences in attentional (N200) and facial perceptual (N170) processing when adults were faced with children of different ethnicities. Furthermore, increased differentiation in attentional processing (N200) for ingroup and outgroup children was associated with reduced cuteness ratings of outgroup children. Importantly however, participants showed no overall preference for ingroup child faces, as motivation to view child faces was even greater towards outgroup child faces. In addition, increased self-reported motivation for parental care was related to enhanced cuteness appraisals of outgroup child faces. Taken together, these findings reveal how early social categorization processes may lead to biased behavior when interacting with children of ethnic minorities.

Oxytocin receptor gene polymorphisms (rs53576) and early paternal care sensitize males to distressing female vocalizations

The oxytocinergic system is highly involved in social bonding and early caregiver-infant interactions. Here, we hypothesize that oxytocin receptor (OXTR) gene genotype and parental bonding history interact in influencing social development. To address this question, we assessed adult males' arousal (heart rate changes) in response to different distress vocalizations (human female, human infant and bonobo). Region rs53576 of the OXTR gene was genotyped from buccal mucosa cell samples, and a self-report Parental Bonding Instrument was used (which provide information about parental care or parental overprotection). A significant gene-environment interaction between OXTR genotype and parenting style was found to influence participants' social responsivity to female cry vocalizations. Specifically, a history of appropriate paternal care in participants accentuated the heightened social sensitivity determined by G/G homozygosity, while higher versus lower paternal overprotection lead to distinct levels of physiological arousal particularly in A carriers individuals. These results add to our understanding of the dynamic interplay between genetic susceptibility and early environmental experience in shaping the development of appropriate social sensitivity in males.

Interactive effects of 5-HTTLPR genotype and rearing environment on affective attitude towards own infant in Japanese mothers

Maternal positive attitude towards one's own infant is the cornerstone of effective parenting. Previous research has revealed an influence of both genetic and environmental factors on maternal parenting behavior, but little is known of the potential gene-environment interaction in shaping a mother's affective attitude. To address this gap, we investigated the effect of a mother's childhood rearing environment and a serotonin transporter gene polymorphism (5-HTTLPR) on affective attitude towards her infant. Our analyses found an interactive effect between rearing environment and 5-HTTLPR genotype on maternal attitude. Specifically, a poor rearing environment (characterized by low maternal care and high paternal overprotection) decreased positive attitude towards one's own infant in mothers with homozygous short allele genotype. In contrast, this detrimental effect was almost eliminated in long allele carriers. Altogether, our results indicate that the 5-HTTLPR gene moderates the influence of experienced rearing environment on maternal parental behavior in a manner consistent with the notion that the short 5-HTTLPR allele amplifies environmental influence.

The development of attachment: Integrating genes, brain, behavior, and environment

In humans, as in other animal species, early caregiver-infant interactions influence physiological and psychological processes by modulating brain sensitivity. Furthermore, early social interaction between caregiver and infant influences infants' cognitive and socioemotional development, and subsequently the development of social, familial, and romantic relationships later in life. Here, we have collected longitudinal and cross-sectional empirical studies as well as review and perspective articles that focus on human or non-human mammals with the aim to investigate how genetic, hormonal, behavioural, and environmental factors, as well as cultural contexts, regulate early interactional experiences, and how these experiences translate into social and non-social competences later in life (see Graphical Abstract).