Mothers' and fathers' neural responses toward gender-stereotype violations by their own children.

Gender stereotypes facilitate people's processing of social information by providing assumptions about expected behaviors and preferences. When gendered expectations are violated, people often respond negatively, both on a behavioral and neural level. Little is known about the impact of family kinship on the behavioral and neural reactions to gender-stereotype violations. Therefore, we examined whether parents show different responses when gender stereotypes are violated by their own children vs unknown children. The sample comprised 74 Dutch families with a father (Mage = 37.54), mother (Mage = 35.83), son, and daughter aged 3-6 years. Electroencephalography measurements were obtained while parents viewed pictures of their own and unknown children paired with toy or problem behavior words that violated or confirmed gender stereotypes. In half of the trials, parents evaluated the appropriateness of toy-gender and behavior-gender combinations. Parents showed stronger late positive potential amplitudes toward gender stereotype-violating behaviors by own children compared to unknown children. Moreover, parents' P1 responses toward gender stereotype-violating child behaviors were stronger for boys than for girls and for parents who evaluated gender-stereotype violations as less appropriate than gender-stereotype confirmations. These findings indicated that gender-stereotype violations by parents' own children are particularly salient and viewed as less appropriate than gender-stereotype confirmations.

Paternal depression in the postpartum year and children's behaviors at age 5 in an urban U.S. birth cohort.

OBJECTIVE: To investigate associations between postpartum depression in fathers and children's behaviors at age 5 in a national high-risk U.S. sample. STUDY DESIGN: A secondary data analysis of 1,796 children in a national birth cohort study that oversampled non-marital births was conducted. Paternal depression was assessed 1 year after the child was born and children's behaviors were assessed by their primary caregivers when the children were 5 years old. Unadjusted and adjusted negative binomial regression models of associations between paternal depression and child behavior scores and logistic regression models of associations between paternal depression and high scores (at least 1.5 or 2.0 standard deviations above the mean) were estimated. RESULTS: In negative binomial regression models that adjusted for child, paternal, and family characteristics and maternal depression, paternal depression was associated with a 17% higher total externalizing behavior score (Incidence Rate Ratio (IRR): 1.17; 95% Confidence Interval (CI): 1.07-1.27), a 17% higher aggressive subscale score (IRR: 1.17; 95% CI: 1.08-1.27), and an 18% higher delinquent subscale score (IRR: 1.18; 95% CI: 1.03-1.35). In adjusted logistic regression models for scores ≥2.0 standard deviations above the mean, paternal depression was associated with high total externalizing scores (e.g., Odds Ratio (OR): 3.09; 95% CI: 1.77-5.41), high aggressive behavior scores (OR: 2.40; 95% CI: 1.30-4.43), and high delinquent behavior scores (OR: 2.08; 95% CI: 1.01-4.27). There were suggestive but non-robust associations between paternal depression and attention problems and no associations between paternal depression and internalizing behaviors or social problems. CONCLUSION: Fathers' depression at age 1 was associated with children's externalizing behaviors at age 5, an important developmental stage when children transition to school. These findings suggest a need to identify and support fathers with depressive symptoms to promote optimal child development.

Stability and inter-family associations of hair endocannabinoid and N-acylethanolamines across the perinatal period in mothers, fathers, and children.

Analysis of endocannabinoids (ECs) and N-acylethanolamines (NAEs) in hair is assumed to retrospectively assess long-term EC/NAE concentrations. To inform their use, this study investigated stability of EC/NAE hair concentrations in mothers, fathers, and their children across the perinatal period as well as associations between family members. In a prospective cohort study, EC (AEA, 1-AG/2-AG) and NAE (SEA, PEA, OEA) levels were quantified in hair samples taken four times in mothers (n = 336) and their partners (n = 225) from pregnancy to two years postpartum and in offspring (n = 319) from shortly after birth to two years postpartum. Across the perinatal period, maternal and paternal hair ECs/NAEs showed poor multiple-test consistency (16-36%) and variable relative stability, as well as inconsistent absolute stability for mothers. Regarding children, hair ECs/NAEs evidenced poor multiple-test consistency (4-19%), no absolute stability, and either no or variable relative stability. Hair ECs/NAEs showed small to medium significant associations across the perinatal period within couples and parent-child dyads. Findings suggest hair ECs/NAEs during the perinatal period possess variable stability in adults, albeit more stability in fathers than mothers in this time. This highlights the need to further investigate factors associated with changes in hair ECs/NAEs across time. The first two years of life may be a dynamic phase for the endocannabinoid system in children, potentially characterized by complex within-family correspondence that requires further systematic investigation.

Perinatal Mental Health: Father Inclusion At The Local, State, And National Levels.

Fathers occupy a dual role in the realm of perinatal mental health: partner and parent. In fathers' role as partners, their support for mothers during pregnancy and postpartum is associated with improved maternal mental health. In their role as parents, fathers themselves are vulnerable to perinatal mood and anxiety disorder. This article aims to advance awareness of paternal perinatal mental health issues and impacts on families. We first review the evidence on paternal perinatal mental health. This evidence includes the critical role played by fathers in maternal perinatal mental health, the prevalence of paternal perinatal mood and anxiety disorder, the impact of paternal mental health on child and family well-being, and screening and treatment approaches. Next, we offer recommendations for more inclusive approaches at the local, state, and national levels aimed at improving parental mental health and health outcomes for fathers, mothers, and babies.

Prevalence of impaired renal function among childless men as compared to fathers: a population-based study.

Male reproductive impairment has been linked with an increased risk of numerous non-communicable diseases. Yet, epidemiological data on renal disease among subfertile men is scarce. Therefore, by using male childlessness as a proxy for male infertility, we aimed to investigate its association with renal function. Data was sourced from a population-based cohort including 22,444 men. After exclusion of men aged < 45 years (n = 10,842), the remaining men were divided into two groups: these being childless (n = 5494) and fathers (n = 6108). Logistic regression was applied to explore the association between male childlessness and renal impairment. Childless men as compared to fathers, were more likely to have an estimated-glomerular filtration rate < 60 ml/min/1.73m2 (OR 1.36, 95 CI 1.08-1.70; p = 0.008). After adjustment for age, marital status, smoking habits, diabetes, hypertension and other components of metabolic syndrome, childless men were also more likely to have dipstick proteinuria (OR 1.85, 95 CI 1.16-2.95; p = 0.01). With the growing panorama of disease associated with male reproductive impairment, men with fertility issues may constitute a target population with potential benefit from closer follow-up of their renal function.

Trans men and paternal pregnancy: experiences during the pregnancy-puerperal period. / Homem trans e gestação paterna: experiências durante o período gravídico-puerperal.

This study aims to analyze the experiences of a transgender man during the gestational-puerperal period and the perspective of obstetric nurses in training based on the dynamics and organization of obstetric healthcare in a hospital setting. This qualitative study is based on a case study approach, employing interviews and direct observations to collect data. The analysis was based on the theoretical and normative framework of the Nursing Process, the Theory of Caring, and the theoretical/critical perspective of transfeminism. The results are organized into six categories: Transgender man in the context of pregnancy, childbirth, and postpartum; partnership and parental dimensions; dilemmas faced by the pregnant couple; impressions recorded by the nursing professional; understanding of the case through a theoretical and epistemological lens; implications for healthcare professionals. We underscore the need to promote spaces for continuing education among healthcare professionals and to reformulate legislation in a way that enables the development of public policies based on respect for diversity and equitable care, recognizing the transgender population's specificities in the contexts of pregnancy, childbirth, and postpartum.

Este estudo objetiva analisar as experiências de um homem trans durante o período gravídico-puerperal e a perspectiva de enfermeiras obstetras em formação, a partir das dinâmicas e da organização dos cuidados de saúde obstétricos em ambiente hospitalar. Trata-se de um estudo de abordagem qualitativa, baseado em estudo de caso, em que utilizou entrevistas e observações diretas para a coleta das informações. A análise foi feita a partir do marco teórico e normativo do Processo de Enfermagem, da Teoria dos Cuidados e da perspectiva teórico/crítica do transfeminismo. Os resultados estão organizados em seis categorias: Homem trans em contexto de gestação, parto e puerpério; parceria e dimensões parentais; dilemas enfrentados pelo casal grávido; impressões registradas pela profissional de enfermagem; compreensão do caso sob a lente teórica e epistemológica; implicações para os profissionais da saúde. Destaca-se a necessidade de promover espaços de educação permanente junto aos profissionais da saúde e reformular legislações de maneira a viabilizar a elaboração de políticas públicas baseada no respeito à diversidade e cuidado equânime, reconhecendo as especificidades da população trans nos contextos da gestação, parto e puerpério.

Digital activism about gay fatherhood on Instagram: male homoparenting in the picture. / Ativismo digital sobre paternidade gay no Instagram: a homoparentalidade masculina em cena.

In contemporary Brazil, the number of male fathers taking care of their sons and daughters and the initiatives to produce content about fatherhood on Instagram have been significant. This article aims to analyze the concepts that support the digital activism of homoparenting on Instagram, based on gender studies with men. To this end, a qualitative study was conducted using the life narrative method in a digital environment. The results were analyzed and divided into the following sections: parenting project, personal experience of fatherhood, articulation with LGBT political agenda when parenthood becomes a "business", and haters, criticism, and adverse reactions. It was concluded that the reflection on the experience of fatherhood/masculinity itself is crossed by the social marker of the difference in sexual orientation and the activism for rights that sustain content production. Thus, the uniqueness of each fatherhood is highlighted since the fact of being gay constructs the fatherhood experience for each man. Despite the initiatives brought forth in this study, changes are still in progress, as rights activism coexists with the advancement of conservative forces, which limit the expressions of sexual and gender otherness.

No Brasil contemporâneo tem sido expressivo tanto o número de homens-pais assumindo o cuidado de seus filhos e filhas, quanto das iniciativas de produção de conteúdo sobre paternidades no Instagram. Este artigo visa analisar as concepções que sustentam o ativismo digital da homoparentalidade no Instagram, a partir dos estudos de gênero com homens. Para tal, realizou-se um estudo qualitativo em ambiência digital, utilizando o método das narrativas de vida. Os resultados foram analisados e divididos nas seguintes seções: projeto de parentalidade; experiência pessoal de paternidade; articulação de agenda política LGBT; quando a paternidade vira um "negócio"; e haters, críticas e reações negativas. Conclui-se que a reflexão sobre a própria experiência de paternidade/masculinidade, atravessada pelo marcador social da diferença orientação sexual e o ativismo por direitos que sustentam a produção de conteúdo. Assim, ressalta-se a singularidade de cada paternidade, pois o fato de ser gay constrói a experiência de paternidade particular para cada homem. Apesar das iniciativas expostas, mudanças ainda são incipientes, visto que o ativismo por direitos coexiste com o avanço de forças conservadoras, que limitam as expressões das alteridades sexuais e de gênero.

Male homoparenting and its challenges: an integrative literature review. / Parentalidade homoafetiva masculina e seus desafios: uma revisão integrativa da literatura.

This study aims to elucidate the challenges faced in the exercise of male homoparenting, through an integrative literature review. Following PRISMA guidelines, empirical studies from the last 22 years were analyzed, independently collected by four researchers using the PubMed and APA PsychNet databases, with the descriptors "Homosexuality, Male" and "Father". The results reveal the unique and complex reality faced by homosexual men in the parental context. While some studies highlight significant challenges, such as stigmas and social prejudices, others do not observe such difficulties. The decision to become a father among homosexual men is influenced by factors specific to their reality, in a context where parenthood is not widely accepted. The findings of this study emphasize the need to understand the complex interactions among individual, social, and cultural factors in male homoparenting. In summary, this study highlights the need for inclusive and diversity-sensitive approaches to support family well-being.

Este estudo visa elucidar os desafios enfrentados no exercício da parentalidade homoafetiva masculina por meio de uma revisão integrativa da literatura. Seguindo as recomendações PRISMA, foram analisados estudos empíricos dos últimos 22 anos, extraídos das bases de dados PubMed e APA PsychNet. Os descritores "Homosexuality, Male" e "Father" foram empregados para a seleção de artigos relevantes, processo realizado independentemente por dois pesquisadores. Os resultados indicam uma complexidade nas experiências parentais de homens homossexuais, variando entre desafios significativos, como estigmas e preconceitos sociais, e situações sem dificuldades notáveis. A decisão de assumir a paternidade nesse grupo é fortemente influenciada por fatores específicos à realidade homoafetiva, inserida em um contexto social frequentemente não acolhedor. Os achados destacam a importância de compreender as interações entre aspectos individuais, sociais e culturais na formação da homoparentalidade masculina. Este estudo sublinha a necessidade de políticas e práticas inclusivas e sensíveis à diversidade, visando o apoio ao bem-estar familiar em contextos homoafetivos.

The ABRAFH and the visibility of homo and transparenthood families. / A ABRAFH e a visibilidade de famílias homotransparentais.

This is an interview conducted by Anna Paula Uziel, a professor at Rio de Janeiro State University, with Saulo Amorim, who was president of ABRAFH (Brazilian Association of Homotransafetive Families), about the history of the Association, its impact on the spread of these family configurations, and how it intersects with the interviewee's fatherhood story. The different characters who make up this story speak about the political moment in the country, the incorporation of transparenthood into ABRAFH. and how it is becoming a space of sociability and comfort for those who practice non-hegemonic parenting.

Entrevista realizada por Anna Paula Uziel, professora da Universidade do Estado do Rio de Janeiro, com Saulo Amorim, que foi presidente da ABRAFH (Associação Brasileira de Família Homotransafetivas), sobre a história da Associação, seus impactos na difusão dessas configurações familiares e como se cruza com a história de paternidade do entrevistado. Os diferentes personagens que compõem essa história falam do momento político do país, da incorporação da transparentalidades à Associação e de como esta vai se constituindo em um espaço de sociabilidade e conforto para quem exerce parentalidades não hegemônicas.

Differences in maternal and paternal pressure to eat and perception of household responsibilities.

Controlling feeding practices, such as pressure to eat, are associated with a child's disinhibited eating and extremes in bodyweight. We aimed to explore which factors are associated with parent dyads' pressuring feeding practices, including how mothers and fathers perceive the sharing of household tasks such as mealtime and child feeding responsibilities. In this cross-sectional study, parent dyads (mother and father) of healthy preschool-aged children completed an identical questionnaire consisting of measures of picky eating (food fussiness subscale of Child Eating Behavior Questionnaire), parental concern for undereating, and pressure to eat (Child Feeding Questionnaire). We used separate multivariable linear regression models for mothers and fathers to assess correlates associated with pressure to eat subscale score, including slowness of eating and enjoyment of food, child BMI z-score and race/ethnicity, and household income. Separate unadjusted linear regression models for mothers and fathers were used to report the association of pressure to eat with household responsibilities. Parents (N = 88) had similar mean picky eating, concern for undereating, and pressure to eat scores; more fathers had high pressure to eat scores (36% vs 27%). Higher pressure to eat was significantly associated with lower income, non-Hispanic Black or Black race/ethnicity, slow eating, and lower enjoyment of food. Pressure was not associated with household responsibilities. While there were similar maternal and paternal perceptions of child eating behaviors, more fathers reported pressuring their child to eat. Identifying differences in parental feeding practices may assist in intervention development to improve feeding practices.

Paternal dietary macronutrient balance and energy intake drive metabolic and behavioral differences among offspring.

Paternal diet can influence the phenotype of the next generation, yet, the dietary components inducing specific responses in the offspring are not identified. Here, we use the Nutritional Geometry Framework to determine the effects of pre-conception paternal dietary macronutrient balance on offspring metabolic and behavioral traits in mice. Ten isocaloric diets varying in the relative proportion of protein, fats, and carbohydrates are fed to male mice prior to mating. Dams and offspring are fed standard chow and never exposed to treatment diets. Body fat in female offspring is positively associated with the paternal consumption of fat, while in male offspring, an anxiety-like phenotype is associated to paternal diets low in protein and high in carbohydrates. Our study uncovers that the nature and the magnitude of paternal effects are driven by interactions between macronutrient balance and energy intake and are not solely the result of over- or undernutrition.

The effects of paternal dietary fat versus sugar on offspring body composition and anxiety-related behavior.

Increasing evidence suggests that the pre-conception parental environment has long-term consequences for offspring health and disease susceptibility. Though much of the work in this field concentrates on maternal influences, there is growing understanding that fathers also play a significant role in affecting offspring phenotypes. In this study, we investigate effects of altering the proportion of dietary fats and carbohydrates on paternal and offspring body composition and anxiety-related behavior in C57Bl/6-JArc mice. We show that in an isocaloric context, greater dietary fat increased body fat and reduced anxiety-like behavior of studs, whereas increased dietary sucrose had no significant effect. These dietary effects were not reflected in offspring traits, rather, we found sex-specific effects that differed between offspring body composition and behavioral traits. This finding is consistent with past paternal effect studies, where transgenerational effects have been shown to be more prominent in one sex over the other. Here, male offspring of fathers fed high-fat diets were heavier at 10 weeks of age due to increased lean body mass, whereas paternal diet had no significant effect on female offspring body fat or lean mass. In contrast, paternal dietary sugar appeared to have the strongest effects on male offspring behavior, with male offspring of high-sucrose fathers spending less time in the closed arms of the elevated plus maze. Both high-fat and high-sugar paternal diets were found to reduce anxiety-like behavior of female offspring, although this effect was only evident when offspring were fed a control diet. This study provides new understanding of the ways in which diet can shape the behavior of fathers and their offspring and contribute to the development of dietary guidelines to improve obesity and mental health conditions, such as anxiety.

Neural processing of cry sounds in the transition to fatherhood: Effects of a prenatal intervention program and associations with paternal caregiving.

This study examined whether neural processing of infant cry sounds changes across the transition to fatherhood (i.e., from the prenatal to postnatal period), and examined whether an interaction-based prenatal intervention modulated these changes. Furthermore, we explored whether postnatal activation in brain regions showing transition or intervention effects was associated with sensitive care and involvement. In a randomized controlled trial, 73 first-time expectant fathers were enrolled, of whom 59 had at least 1 available fMRI scan. Intervention and transition effects on cry processing were analyzed in the amygdala and superior frontal gyrus (SFG) using linear mixed effect models with all available data and with intent-to-treat analyses. Further, exploratory whole-brain analyses were performed. ROI analyses suggest that the transition to fatherhood is characterized by decreasing activation in response to cry vs control sounds in the amygdala but not SFG. Exploratory whole-brain analyses also show a decrease in activation over the transition to fatherhood in the sensorimotor cortex, superior lateral occipital cortex, hippocampus, and regions of the default mode network. In the putamen and insula, larger decreases were found in fathers with more adverse childhood caregiving experiences. In regions showing transitional changes, higher postnatal activation was associated with more concurrent parenting sensitivity. No effects of the intervention were found. The decrease in activation from the pre- to postnatal period may reflect fathers' habituation to cry sounds over repeated exposures. The positive association between postnatal neural activation and paternal sensitive care suggest that continued sensitivity to cry sounds may be conducive to parenting quality.

Parental depression and their children's marriage timing: The long-term consequences of parental mental disorders.

Although decades of research documents powerful associations between parents' characteristics and their children's marital behaviors, the role of parental mental health has largely been ignored, despite the high prevalence of mental disorders and their strong potential to shape multiple dimensions of family life. Many studies examine other consequences of mothers' mental disorders, particularly for young children, but rarely do studies investigate the consequences of fathers' mental disorders, especially the potential for long-term consequences. We construct a theoretical framework for the study of intergenerational influences on family formation behaviors, integrating parental mental health, and emphasizing the potential for father's disorders to shape their children's lives. To investigate these associations, we use new intergenerational panel data featuring clinically validated diagnostic measures of parental mental health for both mothers and fathers, assessed independently. Results demonstrate that fathers' major depressive disorder is associated with significantly earlier marriage timing among sons. These important new findings provide insights into key priorities for social research on family formation processes and intergenerational influences across many domains.

Father's Absence in the Mongolian gerbil (Meriones unguiculatus) is associated with alterations in paternal behavior, T, cort, presence of ERα, and AR in mPOA/ BNST.

Testosterone (T), estrogen receptor alpha (ERα), and androgen receptor (AR) play a significant role in the regulation of paternal behavior. We determined the effects of deprivation of paternal care on alterations in paternal behavior, T concentrations in plasma, and the presence of ERα and AR in the medial preoptic area (mPOA), bed nucleus of the stria terminalis (BNST), medial amygdala (MeA), and olfactory bulb (OB), as well as the corticosterone (CORT) concentrations in plasma caused by deprivation of paternal care in the Mongolian gerbil (Meriones unguiculatus). Twenty pairs of gerbils were formed; the pups were deprived of paternal care (DPC) in 10 pairs. In another 10 pairs, the pups received paternal care (PC). Ten males raised in DPC condition and 10 males raised in PC conditions were mated with virgin females. When they became fathers, each DPC male and PC male was subjected to tests of paternal behavior on day three postpartum. Blood samples were obtained to quantify T and CORT concentrations, and the brains were removed for ERα and AR immunohistochemistry analyses. DPC males gave less care to their pups than PC males, and they had significantly lower T concentrations and levels of ERα and AR in the mPOA and BNST than PC males. DPC males also had higher CORT concentrations than PC males. These results suggest that in the Mongolian gerbil father's absence causes a decrease in paternal care in the offspring, which is associated with alterations in the neuroendocrine mechanisms that regulate it.

Neural correlates of inhibitory control in the context of infant cry and paternal postpartum mental health.

BACKGROUND: Inhibitory control, a form of self-regulation, may support sensitive parenting, but has been understudied in new fathers despite their pronounced risk for stress and mental health challenges. METHODS: This study probed the neural correlates of inhibitory control and its associations to first-time fathers' postpartum mental health, focusing on depressive symptoms, state anxiety, and perceived stress. Six months after their child's birth, 38 fathers self-reported on their mood, anxiety, and stress, and performed a Go/No-Go fMRI task while listening to three sets of sounds (infant cry, pink noise, and silence). RESULTS: Fathers' behavioral inhibition accuracy was consistent across the sound conditions, but their patterns of neural activation varied. Compared to the pink noise condition, fathers showed heightened engagement in prefrontal regulatory regions when self-regulating during the infant cry and silent conditions. When examining correct trials only, results in visual motor area and primary somatosensory cortex emerged only for infant cry and not for pink noise and silence. Moreover, fathers reporting higher levels of postpartum depression, state anxiety, and perceived stress showed greater activation in prefrontal regions when inhibiting during infant cry or silence. CONCLUSION: This study is the first to underscore the complex interplay between the neural mechanisms related to inhibitory control and postpartum mental health and stress across varied auditory context, laying the groundwork for future research.

Impact of miscarriage and termination of pregnancy on subsequent pregnancies: A longitudinal study of maternal and paternal depression, anxiety and eudaimonia.

BACKGROUND: Although miscarriage and termination of pregnancy affect maternal mental illnesses on subsequent pregnancies, their effects on the positive mental health (e.g., eudaimonia) of both first-time and multi-time parents have received minimal attention, especially for fathers. This longitudinal study examines the effects of experiences of miscarriage and termination on parental well-being in subsequent pregnancies from prenatal to postpartum years, while simultaneously considering parity. METHODS: Pregnant women and their partners were recruited during early prenatal visits in Taiwan from 2011 to 2022 and were followed up from mid-pregnancy to 1 year postpartum. Six waves of self-reported assessments were employed. RESULTS: Of 1813 women, 11.3 % and 14.7 % had experiences of miscarriage and termination, respectively. Compared with the group without experiences of miscarriage or termination, experiences of miscarriage were associated with increased risks of paternal depression (adjusted odds ratio = 1.6, 95 % confidence interval [CI] = 1.13-2.27), higher levels of anxiety (adjusted ß = 1.83, 95 % CI = 0.21-3.46), and lower eudaimonia scores (adjusted ß = -1.09, 95 % CI = -1.99 to -0.19) from the prenatal to postpartum years, particularly among multiparous individuals. Additionally, experiences of termination were associated with increased risks of depression in their partner. LIMITATIONS: The experiences of miscarriage and TOP were self-reported and limited in acquiring more detailed information through questioning. CONCLUSIONS: These findings highlight the decreased well-being of men whose partners have undergone termination of pregnancy or experienced miscarriage, and stress the importance of interventions aimed at preventing adverse consequences among these individuals.

A Concept Analysis of Paternal Bonding With Prematurely Born Infants.

BACKGROUND: Maternal bonding in infancy has long been the focus of research and practice. Despite emerging evidence highlighting the importance of paternal bonding, little attention has been focused on fathers. Simultaneously, there is little clarity regarding possible differences between bonding and attachment. PURPOSE: This article aims to clarify the concept of paternal bonding with infants born prematurely. METHODS/SEARCH STRATEGY: Using Walker and Avant's approach to concept analysis, we selected databases and searched them for relevant studies published between 2012 and 2022. We identified 28 articles that (1) defined bonding specific to fathers of infants born prematurely, (2) were peer-reviewed, and (3) were in English. From the articles, we extracted and analyzed data specific to concept definitions, antecedents, and consequences. RESULTS: Regarding paternal bonding with infants born prematurely, our analyses of the 28 studies yielded a conceptual definition of this topic that extends beyond the commonly used definition emphasizing emotional connection. The newly formulated definition covers the cognitive, behavioral, and dynamic, as well as emotional, attributes of bonding. We identify and discuss antecedents and consequences of bonding. IMPLICATIONS FOR PRACTICE AND RESEARCH: Our findings led to a consistent conceptual definition of the bonding phenomenon in question. The definition should serve as a conceptual basis for future guidelines governing clinical practice and research. Through our findings, nurses can better understand and promote paternal bonding with infants born prematurely. Finally, our findings can improve researchers' exploration of this topic.

Selfish conflict underlies RNA-mediated parent-of-origin effects.

Genomic imprinting-the non-equivalence of maternal and paternal genomes-is a critical process that has evolved independently in many plant and mammalian species1,2. According to kinship theory, imprinting is the inevitable consequence of conflictive selective forces acting on differentially expressed parental alleles3,4. Yet, how these epigenetic differences evolve in the first place is poorly understood3,5,6. Here we report the identification and molecular dissection of a parent-of-origin effect on gene expression that might help to clarify this fundamental question. Toxin-antidote elements (TAs) are selfish elements that spread in populations by poisoning non-carrier individuals7-9. In reciprocal crosses between two Caenorhabditis tropicalis wild isolates, we found that the slow-1/grow-1 TA is specifically inactive when paternally inherited. This parent-of-origin effect stems from transcriptional repression of the slow-1 toxin by the PIWI-interacting RNA (piRNA) host defence pathway. The repression requires PIWI Argonaute and SET-32 histone methyltransferase activities and is transgenerationally inherited via small RNAs. Remarkably, when slow-1/grow-1 is maternally inherited, slow-1 repression is halted by a translation-independent role of its maternal mRNA. That is, slow-1 transcripts loaded into eggs-but not SLOW-1 protein-are necessary and sufficient to counteract piRNA-mediated repression. Our findings show that parent-of-origin effects can evolve by co-option of the piRNA pathway and hinder the spread of selfish genes that require sex for their propagation.

Body odours as putative chemosignals in the father-child relationship: New insights on paternal olfactory kin recognition and preference from infancy to adolescence.

Children's body odours are effective chemical cues in the parent-child relationship. Mothers can recognize the odour of their child and prefer this odour over that of unfamiliar children. This effect is mediated by genetic similarity and developmental stage and is therefore suited to promote parental care at pre-pubertal stage, while facilitating incest avoidance at (post-)pubertal stage. The present study tested whether similar mechanisms apply to fathers. Therefore n = 56 fathers evaluated body odour samples of their own and of unfamiliar children in varying genetic and developmental stages. Genetic status was determined by human leucocyte antigen (HLA) profiling, developmental status by standardized assessment of pubertal status and steroid hormone concentration (estradiol, testosterone). Similar to mothers, fathers identified their own child's body odour above chance and preferred that odour. The paternal preference did not relate to HLA similarity but decreased with increasing age of the child. The decline was associated with higher pubertal stages in daughters only, which supports the hypothesis of odour-mediated incest prevention in opposite-sex parent-child dyads.