Testosterone and prolactin are associated with emotional responses to infant cries in new fathers

Paternal peripartum depression: emerging issues and questions on prevention, diagnosis and treatment. A consensus report from the cost action Riseup-PPD

INTRODUCTION

Paternal peripartum depression (P-PPD) is a serious and understudied public health problem associated with impaired family functioning and child development. The lack of recognition of P-PPD may result in limited access to both information and professional help.

OBJECTIVE

The aim of the study was to review studies on paternal peripartum depression and to identify issues and questions where future research and theory formation are needed.

METHODS

A literature search for systematic reviews, meta-analyses and primary studies was conducted using PubMed, Web of Science, Embase, Scopus, Medline, PsychInfo and Informit databases. Key results within the retrieved articles were summarised and integrated to address the review objectives.

RESULTS

Based on the literature, the knowledge related to prevalence, screening, risk factorsunique to fathers, management strategies and outcomes of P-PPD is lacking. Currently, there is no consensual understanding of the definition of P-PPD and recommendations for dealing with P-PPD. Limited data were available regarding the barriers preventing fathers from accessing support systems.

CONCLUSION

Emerging issues that need to be addressed in future research include: P-PPD definition and pathogenetic pathways; prevention strategies and assessment tools; self-help seeking and engagement with interventions; the cost-effectiveness of P-PPD management; needs of health professionals; effect on child development, and public awareness. Future studies and clinical practice should account the complexities that may arise from the father's perceptions of health care services. Results from this review highlights the critical issues on how to plan, provide and resource health services, to meet the health needs of fathers.

Hormonal changes in first-time human fathers in relation to paternal investment

In many biparental species, males experience hormonal changes across the transition to fatherhood that prepare them for their new caregiving role. In humans, cross-sectional comparisons have revealed hormonal differences between fathers and nonfathers, however it is not clear when hormone levels change in new fathers, how such changes relate to paternal involvement and attachment, or even whether men with particular hormonal profiles are more likely to become fathers. In this longitudinal study, we aimed to elucidate the trajectory of hormonal changes in new fathers with greater temporal resolution than previous studies, and to provide further insight into the direction of causality between hormone levels and paternal behavior by asking whether hormone levels predict behavior at subsequent time points, or vice-versa. We recruited a sample of 51 first-time expecting fathers and measured levels of plasma testosterone, oxytocin, vasopressin and cortisol at four time points spanning 4-5 months gestation through 4 months postnatally, and we compared these changes to those found in a control sample of 57 adult male nonfathers. We also examined the concurrent and lagged relationships between hormone levels and fathers' self-reported paternal behaviors. From early in the prenatal period, fathers showed lower levels of both testosterone and vasopressin compared with nonfathers, and lower levels of these hormones during the prenatal period predicted greater postnatal paternal investment in the mother and child. Similar to what is known for human mothers, oxytocin levels increased across the gestational period in new fathers, but oxytocin levels were not associated with greater self-reported paternal involvement or attachment. Finally, cortisol levels did not differ between fathers and nonfathers, and were not predictive of paternal involvement or attachment. Our findings raise the possibility that low levels of vasopressin and testosterone found in expecting fathers anticipate a shift in life history strategy toward greater investment in parenting.

Prevalence and Risk Factors of Paternal Postpartum Depression in Multiple Primary Healthcare Centers in Saudi Arabia: A Cross-Sectional Study

Introduction Paternal postpartum depression (PPPD) is an important public health issue that can negatively affect relationships among fathers, partners, and children. However, research on this issue in Saudi Arabia is lacking. We aimed to determine the prevalence and risk factors for PPPD among Saudi fathers. Methods This cross-sectional study was conducted among Saudi fathers in King Abdulaziz Medical City, Jeddah. We included all fathers of newborns aged ≤6 months while excluding those with a history of depressive disorder. A self-administered questionnaire was sent to all participants. The Arabic version of the Edinburgh Postnatal Depression Scale (EPDS) was used to screen individuals for PPPD. Results The total number of respondents was 223. Approximately 30.9% of participants had PPPD based on an EPDS cutoff value of ≥9. Significant risk factors associated with PPPD were whether the father had lost a child (p = 0.0083) and whether the father had a family history of depression (p = 0.0028). Conclusion Our findings suggest that PPPD is prevalent among Saudi fathers; therefore, there is an urgent need for further research on PPPD. The results of this study will contribute to establishing preventive and intervention programs.

Parenthood and gene expression of oxytocin receptors and vasopressin receptors in sensory cortices of the male California mouse (Peromyscus californicus)

The onset of parental care is associated with shifts in parents' perception of sensory stimuli from infants, mediated by neural plasticity in sensory systems. In new mothers, changes in auditory and olfactory processing have been linked to plasticity at several points along both sensory pathways, including cortical changes that are modulated, at least in part, by oxytocin. In males of biparental species, vasopressin, in addition to oxytocin, is important for modulating parental behavior; however, little is known about sensory plasticity in new fathers. We examined variation in the mRNA expression of oxytocin and vasopressin receptors (Oxtr and Avpr1a) in sensory cortices of virgin males, paired nonbreeding males, and new fathers in the biparental California mouse (Peromyscus californicus), and variation among cortices using the visual cortex for comparison. Reproductive status did not affect gene expression for either receptor, but compared to the visual cortex, expression of both receptors was higher in the left auditory cortex and lower in the anterior olfactory nucleus. Additionally, expression for both receptors was higher in the left auditory cortex compared to the right auditory cortex. While oxytocin and vasopressin receptor expression may remain stable across reproductive stages in male California mice, our findings provide support for auditory cortex lateralization, with the left auditory cortex possibly displaying higher sensitivity to both oxytocin and vasopressin compared to the right.

Stress and parental behaviors

In nearly all mammalian species, newborn pups are weak and vulnerable, relying heavily on care and protection from parents for survival. Thus, developmentally hardwired neural circuits are in place to ensure the timely expression of parental behaviors. Furthermore, several neurochemical systems, including estrogen, oxytocin, and dopamine, facilitate the emergence and expression of parental behaviors. However, stress can adversely affect these systems, impairing parental behaviors. In this review, we will summarize our current knowledge regarding the impact of stress on pup-directed behavior circuits that lead to infant neglect, abuse, and, in extreme cases, killing. We will discuss various stressors that influence parental behaviors at different life stages and how stress induces changes in the neurochemical systems that support parental care, ultimately leading to its poor performance.

Hormonal Actions in the Medial Preoptic Area Governing Parental Behavior: Novel Insights From New Tools

The importance of hormones in mediating a behavioral transition in mammals from a virgin or nonparenting state to parental state was established around 50 years ago. Extensive research has since revealed a highly conserved neural circuit that underlies parental behavior both between sexes and between mammalian species. Within this circuit, hormonal action in the medial preoptic area of the hypothalamus (MPOA) has been shown to be key in timing the onset of parental behavior with the birth of offspring. However, the mechanism underlying how hormones act in the MPOA to facilitate this change in behavior has been unclear. Technical advances in neuroscience, including single cell sequencing, novel transgenic approaches, calcium imaging, and optogenetics, have recently been harnessed to reveal new insights into maternal behavior. This review aims to highlight how the use of these tools has shaped our understanding about which aspects of maternal behavior are regulated by specific hormone activity within the MPOA, how hormone-sensitive MPOA neurons integrate within the wider neural circuit that governs maternal behavior, and how maternal hormones drive changes in MPOA neuronal function during different reproductive states. Finally, we review our current understanding of hormonal modulation of MPOA-mediated paternal behavior in males.

Do Parental Hormone Levels Synchronize During the Prenatal and Postpartum Periods? A Systematic Review

Physiological synchrony is the phenomenon of linked physiological processes among two or more individuals. Evidence of linkage between dyads has been found among a broad range of physiological indices, including the endocrine systems. During the transition to parenthood, both men and women undergo hormonal changes that facilitate parenting behavior. The present review sought to address the question as to whether hormonal synchronization occurs among expecting or new parents. A systematic literature search yielded 13 eligible records. The evidence of cortisol synchrony during the prenatal period, with additional testosterone, prolactin, and progesterone covariations in the time leading up to childbirth, was found to be most significant. During the postpartum period, parental synchrony was reported for oxytocin, testosterone, and cortisol levels. The implications of these covariations were found to translate into adaptive parenting behaviors and the facilitation of romantic bond. Associations with infant development were also reported, suggesting far-reaching effects of hormonal synchrony outside the parental dyad. The results highlight the importance of physiological interrelatedness during this sensitive period, underscoring the need for further research in this field. In view of the limited data available in this research domain, we have put forward a framework for future studies, recommending the adoption of standardized research protocols and repeated collections of specimens.

The intersection between alexithymia, testosterone reactivity, and coparenting in fathers predicts child's prosocial behavior

The development of prosocial skills in children is a key predictor of long-term social, cognitive, and emotional functioning. However, the role of fathers' psychological characteristics in fostering prosocial development, including during the prenatal period, and the mechanisms underlying their influence, remain relatively unexplored. This study aimed to examine whether a higher tendency of alexithymia, a difficulty to identify and verbalize emotions, in expectant fathers predicts prosocial behavior of two-year-old toddlers through the quality of coparenting and whether greater testosterone increase during a stressful parenting task moderates this indirect effect. A sample of 105 couples and their children was tracked longitudinally starting from the third trimester of pregnancy (T1), at three months (T2), and at two years postnatally (T3). Using self-report questionnaires, fathers reported on alexithymia (T1) and mothers and fathers reported on coparenting quality (T2). Additionally, fathers provided saliva samples before and after engaging in a stressful parenting task (the Inconsolable Doll Task) to measure testosterone reactivity (T1). Children's prosocial behavior was observed during an out-of-reach task (T3). A moderated mediation analysis using structural equation modeling showed that higher levels of alexithymia pre-birth predicted lower coparenting quality three months after birth, which in turn predicted lower prosocial behavior of two-year-old children, but only among fathers with mean or high testosterone increases. This study illuminates a potential mechanism by which fathers' alexithymia and testosterone reactivity forecast their toddlers' prosocial behavior.

The Desirable Dad Hypothesis: Male Same-Sex Attraction as the Product of Selection for Paternal Care via Antagonistic Pleiotropy

Same-sex attraction, a heritable trait with a reproductive cost, lacks a comprehensive evolutionary explanation. Here we build on a hypothesis invoking antagonistic pleiotropy, which suggests that genes linked to male same-sex attraction remain in the gene pool because they have conferred some fitness advantage to heterosexual men possessing them. We posit the "desirable dad hypothesis," which proposes that alleles linked to male non-heterosexual orientations increase traits conducive to childcare; heterosexual men possessing same-sex attracted alleles are more desirable mating partners as a function of possessing superior paternal qualities. We conducted three studies to test predictions from this hypothesis. Results were consistent with all three predictions. Study 1 (N = 1632) showed that heterosexual men with same-sex attracted relatives were more feminine than men without, as indicated by self-report measures of femininity (η2 = .007), warmth (η2 = .002), and nurturance (η2 = .004 - .006). In Study 2 (N = 152), women rated feminine male profiles as more romantically appealing than masculine ones (d = 0.83)-but less so than profiles possessing a combination of feminine and masculine traits. In Study 3 (N = 153), women perceived feminine male profiles as depicting the best fathers and masculine profiles the worst (d = 1.56): consistent with the idea that femininity is attractive for childcare reasons. Together, these findings are consistent with the idea that sexual selection for male parental care may be involved in the evolution of male same-sex attraction.

Effects of reproductive status on behavioral and neural responses to isolated pup stimuli in female California mice

The transition to motherhood in mammals is marked by changes in females' perception of and responsiveness to sensory stimuli from infants. Our understanding of maternally induced sensory plasticity relies most heavily on studies in uniparental, promiscuous house mice and rats, which may not be representative of rodent species with different life histories. We exposed biparental, monogamous California mouse (Peromyscus californicus) mothers and ovariectomized virgin females to one of four acoustic and olfactory stimulus combinations (Control: clean cotton and white noise; Call: clean cotton and pup vocalizations; Odor: pup-scented cotton and white noise; Call + Odor: pup-scented cotton and pup vocalizations) and quantified females' behavior and Fos expression in select brain regions. Behavior did not differ between mothers and ovariectomized virgins. Among mothers, however, those exposed to the Control condition took the longest to sniff the odor stimulus, and mothers exposed to the Odor condition were quicker to sniff the odor ball compared to those in the Call condition. Behavior did not differ among ovariectomized virgins exposed to the different conditions. Fos expression differed across conditions only in the anterior hypothalamic nucleus (AHN), which responds to aversive stimuli: among mothers, the Control condition elicited the highest AHN Fos and Call + Odor elicited the lowest. Among ovariectomized virgin females, Call elicited the lowest Fos in the AHN. Thus, reproductive status in California mice alters females' behavioral responses to stimuli from pups, especially odors, and results in the inhibition of defense circuitry in response to pup stimuli.

Testosterone's role in modulating human behaviors relevant to mating and parenting

Testosterone (T) is linked to human mating and parenting. Here, we comprehensively reviewed evidence on whether, in men and women, (1) basal T levels are related to mating and parenting behaviors, (2) T responds to reproduction-relevant cues, (3) acute changes in T map onto subsequent mating and parenting behaviors, and (4) single-dose exogenous T administration causally affects mating and parenting behaviors. We examined whether the available evidence supports trade-off interpretations of T's adaptive function whereby high T levels correspond to greater mating/reproductive effort and competition and low T levels to greater parenting effort and nurturance. We found mixed support for trade-off hypotheses, suggesting that T's function in modulating human mating and parenting might be more nuanced and highly dependent on context and individual trait differences. Results were largely similar for men and women, although studies with women were scarcer than those with men for most behaviors we reviewed.

Father contribution to human resilience

Fathers have been an important source of child endurance and prosperity since the dawn of civilization, promoting adaptation to social rules, defining cultural meaning systems, teaching daily living skills, and providing the material background against which children developed; still, the recent reformulation in the role of the father requires theory-building. Paternal caregiving is rare in mammals, occurring in 3-5% of species, expresses in multiple formats, and involves flexible neurobiological accommodations to ecological conditions and active caregiving. Here, we discuss father contribution to resilience across development. Our model proposes three tenets of resilience - plasticity, sociality, and meaning - and discussion focuses on father-specific contributions to each tenet at different developmental stages; newborn, infant, preschooler, child, and adolescent. Father's style of high arousal, energetic physicality, guided participation in daily skills, joint adventure, and conflict resolution promotes children's flexible approach and social competence within intimate bonds and social groups. By expanding children's interests, sharpening cognitions, tuning affect regulation, encouraging exploration, and accompanying the search for identity, fathers support the sense of meaning, enhancing the human-specific dimension of resilience. We end by highlighting pitfalls to paternal contribution, including absence, abuse, rigidity, expectations, and gender typing, and the need to formulate novel theories to accommodate the "involved dad."

Prenatal prolactin predicts postnatal parenting attitudes and brain structure remodeling in first-time fathers

Despite the important contributions that fathers make to parenting, the neurobiological underpinnings of men's adaptation to parenthood are still not well understood. The current study focuses on prolactin, a hormone that has been extensively linked with reproduction, lactation, and parental behavior in mothers. There is preliminary evidence that prolactin may also reflect the transition to sensitive fatherhood. We sampled prolactin in 91 first-time expectant fathers who participated in a laboratory visit along with their pregnant partners. Fathers' prolactin levels were correlated with their partners' prolactin levels. Men's prolactin levels during their partner's pregnancy were associated with their self-reported antenatal bonding to the unborn infant. Prenatal prolactin levels in fathers also predicted more positive attitudes toward fatherhood at three months postpartum, including lower parenting stress, greater enjoyment of the infant, and a more attunement-oriented parenting style. Within a smaller sample of 32 men who participated in MRI scanning before and after their child's birth, prenatal prolactin also predicted greater reductions in grey matter volume in the left posterior cingulate, left insula, and left nucleus accumbens. In conclusion, men's prenatal prolactin may reflect their perceptions of fatherhood and changes to their perinatal brain structure.

Parental experience is linked with lower vasopressin receptor 1a binding and decreased postpartum androgens in titi monkeys

Parenting induces many neurological and behavioral changes that enable parents to rear offspring. Vasopressin plays an important role in this process via its effects on cognition, affect, and neuroplasticity, and in some cases, via interactions with decreased parental androgens. Thus far, the role of these hormones has been primarily studied in rodents. To address this gap, we explored vasopressin receptors and androgens in titi monkeys, a pair-bonding and biparental primate species. In Studies 1 and 2, we used receptor autoradiography to correlate arginine vasopressin receptor 1a (AVPR1a) binding in the hippocampus (Study 1, n = 10) and the rest of the forebrain (Study 2, n = 23) with parental status, parental experience, parity, infant carrying, and pair affiliation. We found that parents exhibited lower AVPR1a binding than non-parents throughout most brain regions assessed, with especially strong effects in the hippocampus (β = -.61), superior colliculus (β = -.88), lateral septum (β = -.35), and medial preoptic area (β = -.29). The other measures of parental experience also tended to be negatively associated with AVPR1a binding across different brain regions. In Study 3 (n = 44), we compared pre- and postpartum urinary androgen levels in parents and non-parents and found that mothers exhibited a sustained androgen decrease across 3-4 months postpartum (relative to 3 months prepartum; β ranged from -.72 to -.62 for different comparisons). For males, we found that multiparous fathers exhibited decreased androgen levels at 1-2 weeks postpartum (β = -.25) and at 3-4 months postpartum (β = -.40) compared to the prepartum, indicating both immediate and long-term reductions with subsequent paternal experience. Together, the results of this study suggest that decreases in AVPR1a binding and circulating androgens are associated with parental behavior and physiology in titi monkeys.

Postpartum Blues in Fathers: Prevalence, Associated Factors, and Impact on Father-to-Infant Bond

In this study we explored, in men, one of the most common postpartum syndromes in women: the postpartum blues. The aims of the study were (a) to evaluate the prevalence of postpartum blues in fathers, (b) to explore the sociodemographic and perinatal factors that may be associated with its intensity, and (c) to investigate the relationship between the intensity of blues symptoms and the quality of father-to-infant bonding. Three hundred and three French-speaking fathers living in France completed a sociodemographic and obstetrical questionnaire, the Maternity Blues Questionnaire, and the Postpartum Bonding Questionnaire. The fathers were recruited from two maternity hospitals and a Child and Maternal Health Centre within 10 days of their infant's birth, or from online forums devoted to parenting. At least 17.5% of fathers experienced postpartum blues. A high level of education was associated with a higher level of postpartum blues symptoms. Dissatisfaction with the maternity care and significant father involvement during pregnancy and delivery predicted more severe postpartum blues symptoms. Symptoms of postpartum blues were positively correlated with impairment in the father-to-infant bond. This study lends support to the existence of postpartum blues among fathers and highlights its possible consequences on early father-infant relationships.

Functional relationships between estradiol and paternal care in male red-bellied lemurs, Eulemur rubriventer

Fathers contribute substantially to infant care, yet the mechanisms facilitating paternal bonding and interactions with infants are not as well understood as they are in mothers. Several hormonal changes occur as males transition into parenthood, first in response to a partner's pregnancy, and next in response to interacting with the newborn. These changes may prepare fathers for parenting and help facilitate and maintain paternal care. Experimental studies with monkeys and rodents suggest that paternal care requires elevated estradiol levels, which increase when a male's partner is pregnant and are higher in fathers than non-fathers, but its role in the expression of paternal behaviors throughout infant development is unknown. To assess estradiol's role in paternal care, we analyzed the relationship between paternal estradiol metabolites and 1) offspring age, and 2) paternal care behavior (holding, carrying, huddling, playing, grooming), in wild, red-bellied lemurs (Eulemur rubriventer). We collected 146 fecal samples and 1597 h of behavioral data on 10 adult males who had newborn infants during the study. Estradiol metabolites increased four-fold in expectant males, and in new fathers they fluctuated and gradually decreased with time. Infant age, not paternal behavior, best predicted hormone levels in new fathers. These results suggest that hormonal changes occur in expectant males with facultative paternal care, but they do not support the hypothesis that estradiol is directly associated with the day-to-day expression of paternal care. Future research should explore estradiol's role in facilitating behaviors, including infant-directed attention and responsiveness, or preparing fathers for infant care generally.

Proximate and Ultimate Mechanisms of Human Father-child Rough-and-tumble Play

The aim of this contribution is to attempt to understand the adaptive functions of father-child rough-and-tumble play (RTP) in humans. We first present a synthesis of the known proximate and ultimate mechanisms of peer-peer RTP in mammals and compare human parent-child RTP with peer-peer RTP. Next, we examine the possible biological adaptive functions of father-child RTP in humans, by comparing paternal behavior in humans versus biparental animal species, in light of the activation relationship theory and the neurobiological basis of fathering. Analysis of analogies reveals that the endocrine profile of fathers is highly variable across species, compared to that of mothers. This can be interpreted as fathers' evolutionary adjustment to specific environmental conditions affecting the care of the young. Given the high unpredictability and risk-taking features of RTP, we conclude that human adult-child RTP appears to have a biological adaptive function, one of 'opening to the world'.

Hormonal and behavioral responses to an infant simulator in women with and without children

We investigated the impact of maternal status on hormonal reactivity and behavioral responses to an infant simulator in 117 women (54 primiparous, 63 nulliparous). The amount of affectionate touch and motherese were analyzed as behavioral measures of caregiving. Saliva was collected before and 10 min after interaction with the infant simulator to analyze oxytocin, testosterone, cortisol, and estradiol levels. Nulliparous women also provided information about their fertility motivation. Linear mixed models indicated that greater use of affectionate touch was associated with lower overall testosterone levels. Cortisol decreased in response to the interaction in both groups. In the primiparous group, the amount of affectionate touch associated inversely with cortisol levels, whereas in the nulliparous group such association was not found. Oxytocin or estradiol reactivity to the simulator did not differ between the groups, nor were these hormones associated with behavior. Higher fertility motivation in nulliparous women was related to more motherese, and lower testosterone levels. Our results indicate that the simulator elicits hormonal reactivity both in mothers and nonmothers, but the patterns of associations between caregiving behavior and hormonal levels may be partially different. These results encourage using the infant simulator to explore hormonal processes related to the transition to parenthood.

Is paternal oxytocin an oxymoron? Oxytocin, vasopressin, testosterone, oestradiol and cortisol in emerging fatherhood

How do hormonal levels in men change from pregnancy to after the birth of their firstborn child, and what is the role of oxytocin, alone or in interplay with other hormones, in explaining variance in their parenting quality? We explored in 73 first-time fathers the development of five hormones that have been suggested to play a role in parenting: oxytocin (OT), vasopressin (AVP), testosterone (T), oestradiol (E2) and cortisol (Cort). In an extended group of fathers (N = 152) we examined associations with fathers' behaviour with their 2-month-old infants. OT and E2 showed stability from the prenatal to the postnatal assessments, whereas AVP and T decreased significantly, and Cort decreased marginally. OT on its own or in interplay with other hormones was not related to paternal sensitivity. Using an exploratory approach, the interaction between T and E2 emerged as relevant for fathers' sensitive parenting. Among fathers with high E2, high T was associated with lower sensitivity. Although we did not find evidence for the importance of OT as stand-alone hormone or in interplay with other hormones in this important phase in men's lives, the interaction between T and E2 in explaining variation in paternal behaviour is a promising hypothesis for further research. This article is part of the theme issue 'Interplays between oxytocin and other neuromodulators in shaping complex social behaviours'.

Motivational increase of androgens and behavior by infant distress calls in highly responsive common marmoset fathers, Callithrix jacchus

Common marmoset fathers are highly involved in care of their infants. However, variability exists in their response to infant behavior even in paternally experienced fathers. Using infant distress cries as a motivation test, we investigated: 1. the differences in paternally experienced fathers' motivation to search for the infant vocalization stimuli; 2. the relationship between a father's motivation to search for the source of the infant cries and testosterone levels; and 3. if there is a rapid steroidogenesis pathway leading to increased testosterone and estradiol in the peripheral circulation. Only 44% of the paternally experienced fathers showed a high frequency of searching for the source of the infant distress cries. Through the use of multisteroid analysis, we found high responsive fathers had significantly higher levels of progesterone and testosterone in response to infant distress cries compared to a control stimulus with progesterone and androstenedione correlating with testosterone, while no differences were seen in low responders. The frequency to search for the infant stimuli was positively correlated with higher testosterone compared to control vocal levels. These results suggest that searching for the source of infant cries represents a motivation behavior for fathers that is activated by testosterone and reflects rapid circulating testosterone.

Cortisol and testosterone concentrations during the prenatal and postpartum period forecast later caregiving quality in mothers and fathers

Given that parental caregiving quality affects child development from birth onwards, it is important to detect parents who are at risk for low-quality caregiving as early as possible, preferably before or soon after birth. This study investigated whether cortisol (CORT) and testosterone (T) measured during the last trimester of pregnancy and six weeks postpartum were associated with observed caregiving quality at child age 3 in mothers (N = 63) and fathers (N = 45). CORT and T were measured during an interaction with a simulator infant (pregnancy) and their own infant (postpartum). In mothers, no associations were found with CORT and T during pregnancy, but higher postpartum CORT during a mother-infant interaction was related to higher caregiving quality during toddlerhood. In fathers, the association between T during pregnancy and caregiving quality in toddlerhood was more negative for fathers with low CORT. In contrast to mothers, higher postpartum CORT in fathers was associated with lower caregiving quality in toddlerhood. These findings proved robust after applying the Benjamini-Hochberg procedure to control for false discovery rate. Our findings indicate that CORT and T during the perinatal period can forecast caregiving quality in both mothers and fathers. Moreover, our results provided evidence for the dual-hormone hypothesis, but only in fathers. These findings contribute to our growing understanding on how endocrine measures explain individual differences in caregiving quality in mothers and fathers.

The Role of Paternal Involvement on Behavioral Sensitive Responses and Neurobiological Activations in Fathers: A Systematic Review

As fathering research has flourished, a growing body of studies has focused on behavioral and neurobiological mechanisms, respectively associated with caregiving sensitivity and responsiveness to infant stimuli. However, the association between these aspects and the key concept of paternal involvement in childcare (i.e., contribution in infant care in terms of time, availability, and responsibility) has been poorly investigated. The current work aims to systematically review the role of involvement in childcare on both neural activations and sensitive behaviors in fathers by examining (a) how paternal involvement has been measured and (b) whether paternal involvement has been associated with neurobiological activation and behavioral sensitive responses. Inclusion criteria were peer-reviewed quantitative studies, concerning fathers responding to infant stimuli at neurobiological or behavioral level, and including a quantitative measurement of paternal involvement in childcare. A quality rating for each study has been performed based on the measurements adopted to assess paternal involvement. Of 2,529 articles, 27 studies were included. According to our quality rating, 10 out of 27 studies included fairly good-standard measures for measuring paternal involvement, whereas 17 studies used good-standard measures. In addition, 11 studies provided details of paternal involvement in the context of neurobiological responses to infant stimuli, whereas 16 addressed paternal sensitive behaviors. Overall, only 8 studies reported relevant findings about the relationship between paternal involvement and neurobiological responses or sensitive behaviors in fathers. The present study is the first systematically evaluating the scope of paternal involvement in the field of Paternal Brain and fathers' sensitive responsiveness research. When high-standard measures are used, paternal involvement seems to play a significant role in modulating both the hormonal and the neural pathways associated with paternal behaviors. Remarkably, the role of paternal engagement may underpin an adaptive nurturance that is not dependent on pregnancy and childbirth but on caregiving experience. A promising positive link between paternal involvement and behavioral sensitivity may be expected in further studies, which will need to corroborate our conclusion by adopting detailed and appropriate measures assessing paternal involvement. As a future line of research, the inclusion of gay fathers may be beneficial for the field.

Hormones and neuroplasticity: A lifetime of adaptive responses

Major life transitions often co-occur with significant fluctuations in hormones that modulate the central nervous system. These hormones enact neuroplastic mechanisms that prepare an organism to respond to novel environmental conditions and/or previously unencountered cognitive, emotional, and/or behavioral demands. In this review, we will explore several examples of how hormones mediate neuroplastic changes in order to produce adaptive responses, particularly during transitions in life stages. First, we will explore hormonal influences on social recognition in both males and females as they transition to sexual maturity. Next, we will probe the role of hormones in mediating the transitions to motherhood and fatherhood, respectively. Finally, we will survey the long-term impact of reproductive experience on neuroplasticity in females, including potential protective effects and risk factors associated with reproductive experience in mid-life and beyond. Ultimately, a more complete understanding of how hormones influence neuroplasticity throughout the lifespan, beyond development, is necessary for understanding how individuals respond to life changes in adaptive ways.

Child maltreatment affects fathers’ response to infant crying, not mediated by cortisol or testosterone

Parents' ability to appropriately respond to infant crying is essential for parental care and has been found to relate to parents' own childhood experiences. Additionally, childhood experiences can affect endocrine factors, which may subsequently affect behavior. In the current study, preregistered on https://osf.io/hwgtu, we examined in expectant and new fathers (N = 152) associations between experiences of maltreatment in their own childhood, hair cortisol and testosterone concentrations and their ability to modulate handgrip force when exposed to infant crying. Cortisol and testosterone were quantified from the 1 cm of hair most proximal to the scalp using Liquid chromatography-tandem mass spectrometry. Participants were asked to squeeze a handgrip dynamometer at full and half strength while listening to infant cries and control sounds. Results indicated that fathers who experienced more childhood maltreatment used more excessive handgrip force during infant cry sounds. Hair cortisol and testosterone were not related to either experienced childhood maltreatment or handgrip strength modulation. These findings confirm that fathers’ early experiences of maltreatment reduce their ability to modulate their behavioral responses during infant cries, but suggest that hair cortisol and testosterone concentrations do not identify the underlying mechanism of this association.

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Childhood maltreatment relates to fathers' behavioural responses to infant crying.

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Childhood maltreatment is unrelated to fathers' hair cortisol and testosterone.

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Cortisol and testosterone are unrelated to behavioural responses to infant cries.

Preliminary data on increased reactivity towards children in distress after testosterone administration in women: A matter of protection?

Emotional reactivity to others' distress is a vital prerequisite for a caring response. Testosterone, in contrast, is mostly associated with protection of personal dominance and decreased responsiveness to others' needs. However, experimental work also indicates that rising testosterone levels in response to infant distress can potentially facilitate protection. We assessed the impact of testosterone administration on participants' emotional reactivity to infants in distress, measuring their facial responses on the corrugator supercilii forehead muscle ('frowning') and the zygomaticus major ('smiling') as an index of emotional responses towards children. Moreover, we probed whether the effect of testosterone is moderated by participants' self-reported nurturance and protective tendencies. Our preliminary results showed that testosterone not only increased emotional reactivity to empathy eliciting images of children, but that this increase was strongest in participants with strong protective tendencies. Our administration study is the first to link testosterone to infant protection.

Not all "caregivers" are created equal: Liking, caring and facial expression responses to the baby schema as a function of parenthood and testosterone

The baby schema elicits care from potential caregivers. However, much of the research on the baby schema is based on self-report only. To address this issue, we explored the effects of baby schema and child age on facial expressions (EMG) and eye-blink startle, in addition to self-reported liking and caring for 43 men and 48 women (39 parents). Further, basal testosterone was assessed. All groups responded with liking and caring to high baby schema, but only women also responded with more positive facial expressions. Caring and smiling towards infants compared to first graders depended on parenthood and testosterone levels. Basal testosterone levels were negatively associated with overall responsiveness to children in women and fathers, but positively in non-fathers. Whereas the baby schema overall lead to positive affect and caring, the scope of these responses and the processes underlying them depended on gender, parenthood and hormonal status.

How do expectant fathers respond to infant cry? Examining brain and behavioral responses and the moderating role of testosterone

Expectant parents’ responses to infant cry may indicate future risk and resiliency in the parent-child relationship. Most studies of parental reactivity to infant cry have focused on mothers, and few studies have focused on expectant fathers, although fathers make important contributions to parenting. Additionally, although different responses to infant cry (behavioral, psychological and neural) are hypothesized to track together, few studies have analyzed them concurrently. The current investigation aimed to address these gaps by characterizing multimodal responses to infant cry within expectant fathers and testing whether prenatal testosterone moderates these responses. Expectant fathers responded to infant cry vs frequency-matched white noise with increased activation in bilateral areas of the temporal lobe involved in processing speech sounds and social and emotional stimuli. Handgrip force, which has been used to measure parents’ reactivity to cry sounds in previous studies, did not differentiate cry from white noise within this sample. Expectant fathers with higher prenatal testosterone showed greater activation in the supramarginal gyrus, left occipital lobe and precuneus cortex to cry sounds. Expectant fathers appear to interpret and process infant cry as a meaningful speech sound and social cue, and testosterone may play a role in expectant fathers’ response to infant cry.

Fathers' oxytocin responses to first holding their newborns: Interactions with testosterone reactivity to predict later parenting behavior and father-infant bonds

Little is known about human fathers' physiology near infants' births. This may represent a period during which paternal psychobiological axes are sensitive to fathers' new experiences of interacting with their newborns and that can provide insights on how individual differences in fathers' biology relate to post-partum parenting. Drawing on a sample of men in South Bend, IN (U.S.), we report results from a longitudinal study of fathers' oxytocin, cortisol, and testosterone (N = 211) responses to their first holding of their infants on the day of birth and men's reported caregiving and father-infant bonding at 2-4 months post-partum (N = 114). First-time fathers' oxytocin was higher following first holding of their newborns, compared to their pre-holding levels. Contrasting with prior results, fathers' percentage change in oxytocin did not differ based on skin-to-skin or standard holding. Drawing on psychobiological frameworks, we modeled the interactions for oxytocin reactivity with testosterone and cortisol reactivity, respectively, in predicting father-infant outcomes months later. We found significant cross-over interactions for (oxytocin × testosterone) in predicting fathers' later post-partum involvement and bonding. Specifically, we found that fathers whose testosterone declined during holding reported greater post-partum play if their oxytocin increased, compared to fathers who experienced increases in both hormones. We also observed a similar non-significant interaction for (oxytocin × cortisol) in predicting fathers' post-partum play. Fathers whose testosterone declined during holding also reported less involvement in direct caregiving and lower father-infant bonding if their oxytocin decreased but greater direct care and bonding if their testosterone increased and oxytocin decreased. The results inform our understanding of the developmental time course of men's physiological responsiveness to father-infant interaction and its relevance to later fathering behavior and family relationships.

[Hormonal influence on hearing]

BACKGROUND

Hearing loss leads to impairments in communication, social interactions, and cognitive functions. This renders early treatment particularly important. A causal therapy is not yet available. Human and animal studies have shown that certain hormones can have a positive effect on hearing.

OBJECTIVE

This review provides an overview of the effects of various hormones on hearing and describes the potential benefit for future therapeutic approaches.

MATERIALS AND METHODS

A systematic literature review of reviews dealing with the effects of various hormones on hearing in humans and animals published in PubMed between 2015 and 2020 was conducted.

RESULTS

Hormones may mediate antiapoptotic effects on structure-relevant cells of the cochlea and auditory pathway, and may influence hair cell functionality or the electrolyte balance of the endo- and perilymph. Current research focuses on glucocorticoids; the mineral corticoid aldosterone; the sex hormones estrogen, progesterone, and testosterone; the growth hormones GH (growth hormone) and IGF‑1 (insulin-like growth factor 1); thyroid hormones; and insulin. Study results are still inconsistent at this time, but various hormones appear to represent a possible future treatment option for acute hearing loss. Long-term hormone treatment, which would be necessary particularly in the case of age-related hearing loss, does not currently represent a sensible course of action due to the side effect profile of the systemic treatment/lack of practicable topical application options.

CONCLUSION

The mode of action of hormones is complex. Whether they can be used in the future for individualized treatment of patients with acute hearing impairment requires further investigation.

Changes in Fathers' Body Mass Index, Sleep, and Diet From Prebirth to 12 Months Postbirth: Exploring the Moderating Roles of Parenthood Experience and Coparenting Support

BACKGROUND

While research has examined prenatal to postnatal changes in women's weight, sleep, and diet, much less is known about these changes among fathers.

PURPOSE

This study aimed to (a) examine changes in fathers' body mass index (BMI), sleep, and diet from 1 month before birth to 5-6 months following birth, and from 5-6 months to 11-12 months following birth and (b) explore the moderating roles of parenthood experience and coparenting support.

METHODS

169 fathers (mean age 35.5 years, 58.9% White) participated. Fathers completed an intake survey shortly after their infant's birth to recall their height and weight, nighttime sleep hours, fruit and vegetable intake, soda intake, and fast food intake for the month prior to birth. When their child was 6 and 12 months old, fathers reported their weight, sleep, and diet again for the past 4 weeks (i.e., 4 week periods spanning 5-6 months and 11-12 months following birth). Generalized estimating equations were used to answer our research questions.

RESULTS

Fathers reported higher BMI (Δ = 0.22 kg/m2; 95% confidence interval [CI] = 0.06, 0.38; p = .008) and less nighttime sleep duration (Δ = -0.21 hr; 95% CI = -0.38, -0.05; p = .012) at 5-6 months following birth compared to 1 month prior to birth. Fathers' diet remained stable over the three timepoints. No evidence was found to support the moderating roles of parenthood experience and coparenting support on fathers' weight and behavior changes.

CONCLUSIONS

5-6 months following birth may be an important point of intervention for fathers to promote a return to prebirth BMI and sleep levels.

The neural correlates of paternal consoling behavior and frustration in response to infant crying

Human fathers often form strong attachments to their infants that contribute to positive developmental outcomes. However, fathers are also the most common perpetrators of infant abuse, and infant crying is a known trigger. Research on parental brain responses to infant crying have typically employed passive listening paradigms. However, parents usually engage with crying infants. Therefore, we examined the neural responses of 20 new fathers to infant cries both while passively listening, and while actively attempting to console the infant by selecting soothing strategies in a video game format. Compared with passive listening, active responding robustly activated brain regions involved in movement, empathy and approach motivation, and deactivated regions involved in stress and anxiety. Fathers reporting more frustration had less activation in basal forebrain areas and in brain areas involved with emotion regulation (e.g., prefrontal cortex and the supplementary motor area). Successful consolation of infant crying activated regions involved in both action-outcome learning and parental caregiving (anterior and posterior cingulate cortex). Overall, results suggest that active responding to infant cries amplifies activation in many brain areas typically activated during passive listening. Additionally, paternal frustration during active responding may involve a combination of low approach motivation and low engagement of emotion regulation.

Being the Father of a Preterm-Born Child: Contemporary Research and Recommendations for NICU Staff

Background: Most studies on parental reactions to a preterm birth and to hospitalization of the newborn in Neonatal Intensive Care Units (NICUs) have involved mothers. However, emotional responses and behaviors of fathers are equally important. Usually, the father is the first to meet the preterm newborn, to find out information about baby's condition and to communicate to the mother and other family members. In this context he is often left alone and can show psychological difficulties including affective disorders such as depression or anxiety. This paper describes the role of fathers in the NICU, the best practices to support fathers, and to explain the role of a psychologist in the NICU staff. Considerations and suggestions are provided on the difficulties encountered to support parents, with a focus on the role of fathers during the COVID-19 pandemic. Methods and Discussion: Considering contemporary research data and following an attachment perspective, we analyze the role of the father of a preterm-born child in the relation with the partner and in newborn caring. Research has shown that involving fathers in newborn care in NICU and at home is essential not only because it promotes the father/son attachment relationship and has positive effects on the psychological and somatic development of the newborn, but also for the health of the mother and whole family. Conclusion: Recommendations are provided to enhance the functions of fathers in the NICU, promote their involvement in the care of their infant, and interventions to prevent the manifestation of psychological suffering and/or perinatal affective disorders. The commitments of a psychologist in a NICU team are presented and require not only clinical skills, but also the ability to manage the emotional and relational difficulties of fathers, family and NICU staff. Considerations and suggestions are provided on the difficulties encountered by parents in the NICU during the COVID-19 pandemic.

The postnatal testosterone rebound in first-time fathers and the quality and quantity of paternal care

In human males, testosterone (T) decreases in the period following the birth of offspring. This decline has been widely interpreted as a facultative neuroendocrine response that facilitates parenting effort. Conversely, research on if (or when) this decline in T would be followed by an eventual recovery and subsequent shift away from parenting effort is lacking. In a U.S. community sample of 225 males transitioning to first-time fatherhood, we measured T at three occasions: third trimester, infant 3 months postnatal, and infant 9-10 months postnatal. Using a piecewise latent growth curve model (GCM), we detected a T rebound from when infants were 3 months old to when infants were 9-10 months old. The slope of this rebound was able to predict paternal care using two distinct measures: (a) an experience sampling method (ESM) that gathered data on paternal time allocation over the course of the study period and (b) independent coders rating fathers for the quality of paternal care during a structured task designed to elicit an infant fear response. As predicted, the more accelerated one's T rebound (slope), the less time fathers invested in their infants across the study period. However, we found a positive relationship between T rebound and quality of paternal care during a challenging activity. Discussion will focus on nuanced reasons that contribute to these findings as well as speculate on the ultimate function of a human paternal T rebound.

A new data-driven mathematical model dissociates attractiveness from sexual dimorphism of human faces

Human facial attractiveness is evaluated by using multiple cues. Among others, sexual dimorphism (i.e. masculinity for male faces/femininity for female faces) is an influential factor of perceived attractiveness. Since facial attractiveness is judged by incorporating sexually dimorphic traits as well as other cues, it is theoretically possible to dissociate sexual dimorphism from facial attractiveness. This study tested this by using a data-driven mathematical modelling approach. We first analysed the correlation between perceived masculinity/femininity and attractiveness ratings for 400 computer-generated male and female faces (Experiment 1) and found positive correlations between perceived femininity and attractiveness for both male and female faces. Using these results, we manipulated a set of faces along the attractiveness dimension while controlling for sexual dimorphism by orthogonalisation with data-driven mathematical models (Experiment 2). Our results revealed that perceived attractiveness and sexual dimorphism are dissociable, suggesting that there are as yet unidentified facial cues other than sexual dimorphism that contribute to facial attractiveness. Future studies can investigate the true preference of sexual dimorphism or the genuine effects of attractiveness by using well-controlled facial stimuli like those that this study generated. The findings will be of benefit to the further understanding of what makes a face attractive.

Testosterone and cortisol are negatively associated with ritualized bonding behavior in male macaques

Neuroendocrine research on the formation of social bonds has primarily focused on the role of nonapeptides. However, steroid hormones often act simultaneously to either inhibit or facilitate bonding. Testosterone is proposed to mediate a trade-off between male mating effort and nurturing behavior; therefore, low levels are predicted during periods of nurturing infant care and social bonding. In species where social bonding and support regulates hypothalamic-pituitary-adrenal axis activity, we also expect glucocorticoid levels to be low during bonding periods. We investigated how immunoreactive urinary testosterone (iuT) and cortisol (iuC) were related to triadic male-infant-male interactions - a ritualized male bonding behavior - as well as infant care in male Barbary macaques (Macaca sylvanus). We collected >3000 h of behavioral observation data during full-day focal animal follows from 14 adult males and quantified iuT and iuC from 650 urine samples. iuT was negatively correlated with rates of triadic interactions within subjects, but positively correlated between subjects. iuC was negatively correlated with triadic interactions both within and between subjects. Time spent caring for infants was positively correlated to both iuT and iuC within subjects, but not between subjects. The observed negative relationship between iuT and triadic interactions within subjects may be beneficial to lower competitive tendencies between adult males and to not inhibit bond formation. However, the positive correlation of iuT with triadic interactions between subjects was unexpected. We speculate that it could be due to a link between triadic interactions and coalition formation. A negative relationship between triadic interactions and iuC could reflect increased bonding and perceived social support as triadic interactions predict future coalition formation in this species, or reflect buffered tensions between males. The positive relationship of iuT and iuC with infant care suggests that the handling of infants may be less nurturing but rather protective or competitive in this species. Measuring steroid hormones in relation to bonding and nurturing can help us interpret behaviors within the ecological contexts that they occur.

Changes in prenatal testosterone and sexual desire in expectant couples

During the transition to parenthood (TTP), both women and men report declines in sexual desire, which are thought to reflect an evolutionarily adaptive focus on parenting over mating. New parents also show changes in testosterone, a steroid hormone implicated in both parenting and mating, suggesting that changes in sexual desire may be associated with changes in testosterone. To test these associations, we followed a sample of heterosexual couples expecting their first child across the prenatal period. We examined prenatal changes in testosterone and two forms of sexual desire (solitary, dyadic). Expectant mothers showed prenatal increases in testosterone, and women's higher testosterone was associated with lower dyadic desire. Expectant fathers showed prenatal decreases in testosterone, and declines in men's testosterone were associated with lower dyadic desire. Testosterone was unrelated to men's or women's solitary desire. Our findings provide support for the idea that prenatal changes in testosterone contribute to an evolutionarily adaptive focus on parenting over mating during the TTP.

A Neuro-hormonal Circuit for Paternal Behavior Controlled by a Hypothalamic Network Oscillation

Parental behavior is pervasive throughout the animal kingdom and essential for species survival. However, the relative contribution of the father to offspring care differs markedly across animals, even between related species. The mechanisms that organize and control paternal behavior remain poorly understood. Using Sprague-Dawley rats and C57BL/6 mice, two species at opposite ends of the paternal spectrum, we identified that distinct electrical oscillation patterns in neuroendocrine dopamine neurons link to a chain of low dopamine release, high circulating prolactin, prolactin receptor-dependent activation of medial preoptic area galanin neurons, and paternal care behavior in male mice. In rats, the same parameters exhibit inverse profiles. Optogenetic manipulation of these rhythms in mice dramatically shifted serum prolactin and paternal behavior, whereas injecting prolactin into non-paternal rat sires triggered expression of parental care. These findings identify a frequency-tuned brain-endocrine-brain circuit that can act as a gain control system determining a species’ parental strategy.

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Species-specific hypothalamic dopamine neuron rhythms yield distinct prolactin release

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Serum prolactin primes the “parental” neural circuit for pup care during fatherhood

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Optogenetic control of TIDA frequency tunes prolactin and paternal behavior

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Prolactin receptors in the MPOA are required for paternal behavior

The challenge hypothesis revisited: Focus on reproductive experience and neural mechanisms

Our review focuses on findings from mammals as part of a Special Issue "30th Anniversary of the Challenge Hypothesis". Here we put forth an integration of the mechanisms through which testosterone controls territorial behavior and consider how reproductive experience may alter these mechanisms. The emphasis is placed on the function of socially induced increases in testosterone (T) pulses, which occur in response to social interactions, as elegantly developed by Wingfield and colleagues. We focus on findings from the monogamous California mouse, as data from this species shows that reproductive status is a key factor influencing social interactions, site fidelity, and vigilance for offspring defense. Specifically, we examine differences in T pulses in sexually naïve versus sexually experienced pair bonded males. Testosterone pulses influence processes such as social decision making, the winner-challenge effect, and location preferences through rewarding effects of T. We also consider how social and predatory vigilance contribute to T pulses and how these interactions contribute to a territory centered around maximizing reproduction. Possible underlying mechanisms for these effects include the nucleus accumbens (rewarding effects of testosterone), hippocampus (spatial memories for territories), and the bed nucleus of the stria terminalis (social vigilance). The development of the challenge effect has provided an ideal framework for understanding the complex network of behavioral, environmental, physiological and neural mechanisms that ultimately relates to competition and territoriality across taxa. The opportunity to merge research on the challenge effect using both laboratory and field research to understand social behavior is unparalleled.

Life history and individual differences in male testosterone: Mixed evidence for early environmental calibration of testosterone response to first-time fatherhood

Male testosterone (T) decreases in response to childbirth. Longitudinal support for this has come from samples across cultures. In this study, we look at individual differences in this phenomenon. Utilizing a sample of U.S. fathers, we employ life history theory to investigate the influence of a father's early experience on his neuroendocrine response to fatherhood. We conducted three home visits (n = 226 fathers) from the third trimester of pregnancy to when infants were 10 months old. In this sample, T declined from the third trimester of (a partner's) pregnancy to the early months of the postnatal period. T recovered to pre-birth levels by the time infants reached 10 months old. We did not find any evidence that one's subjective experience of their early environment could account for any meaningful variability in T calibration. Objective, "event" measures of early harshness (i.e., death of a sibling/friend) and unpredictability (i.e., parent upheaval) each uniquely predicted a younger age of sexual debut. Neither harshness nor unpredictability had any (direct or indirect) effects on T calibration. Age of sexual debut did predict the rate of T recovery from 3 to 10 months postnatal. The younger one's sexual debut, the more accelerated their T ascent during this period. We discuss the potential reasons for, and implications of our mixed results.

The unique social sense of puerperium: Increased empathy and Schadenfreude in parents of newborns

Pregnancy and puerperium are typified by marked biobehavioral changes. These changes, which are traceable in both mothers and fathers, play an important role in parenthood and may modulate social cognition abilities. However, the latter effects remain notably unexplored in parents of newborns (PNs). To bridge this gap, we assessed empathy and social emotions (envy and Schadenfreude) in 55 PNs and 60 controls (childless healthy participants without a romantic relationship or sexual intercourse in the previous 48 hours). We used facial electromyography to detect physiological signatures of social emotion processing. Results revealed higher levels of affective empathy and Schadenfreude in PNs, the latter pattern being accompanied by increased activity of the corrugator suppercilii region. These effects were not explained by potential confounding variables (educational level, executive functioning, depression, stress levels, hours of sleep). Our novel findings suggest that PNs might show social cognition changes crucial for parental bonding and newborn care.

Perception of male and female infant cry aversiveness by adult men

Objective: The study aimed to determine why male infants are abused more frequently than female infants.Background: Infant crying is a well-known trigger for Shaken Baby Syndrome or Abusive Head Trauma (SBS/AHT). For unknown reasons, male infants are more often victims of SBS/AHT than female infants. We hypothesised that this sex difference in victimisation was attributable to either acoustic or movement differences between male and female infants when crying, or to gender stereotypes about infant crying (e.g. 'boys don't cry').Methods: Adult male participants rated auditory and video cry stimuli from male and female infants for aversiveness. Each infant was rated while wearing both blue and pink clothing to denote male or female gender.Results: In two experiments, male infants spent more time producing expiratory phonations than did female infants, and this variable was positively correlated with aversiveness ratings. Including visual stimuli increased male but not female infant cry aversiveness compared with audio stimuli alone. Finally, dressing infants in blue did not increase cry aversiveness.Conclusions: These findings suggest that both the tendency of male infants to produce more expiratory phonations when crying, as well as their visual appearance when crying, may contribute to their increased vulnerability to abuse.

Dads: Progress in understanding the neuroendocrine basis of human fathering behavior

We outline the progress on the hormonal basis of human paternal behavior during the past twenty years. Advances in understanding the roles of testosterone, prolactin, oxytocin and vasopressin in fathering behavior are described, along with recent research on hormonal interactions, such as those between testosterone and cortisol, and testosterone and the peptide hormones. In addition, we briefly describe the recent leaps forward in elucidating the neurobiological and neuroendocrine basis of fatherhood, made possible by fMRI technology. Emerging from this literature is a developing and complicated story about fatherhood, highlighting the need to further understand the interplay between behavior, physiology, social context, and individual genetic variation. Given the changing roles of parents in many societies, the continued growth of this research area will provide a strong empirical knowledge base about paternal behavior on which to create policies promoting fathers' involvement in their infants' lives.

When Fathers Begin to Falter: A Comprehensive Review on Paternal Perinatal Depression

The transition to parenthood is considered to be a major life transition that can increase the vulnerability to parental depressive disorders, including paternal perinatal depression (PPND). Although it is known that many fathers experience anxiety and depression during the perinatal period, PPND is a recent diagnostic entity and there are not enough published studies on it. Accordingly, its prevalence and epidemiology are still not well defined, although the majority of studies agree that PPND is less frequent than maternal perinatal depression and postpartum depression. Nevertheless, PPND is different from maternal perinatal mental health disorders, usually, fathers have less severe symptoms, and mood alterations are often in comorbidity with other affective disorders. Despite the absence of DSM-5 diagnostic criteria and the fluctuation of prevalence rates, clinical symptoms have been defined. The main symptoms are mood alterations and anxiety, followed by behavioral disturbances and concerns about the progress of pregnancy and the child’s health. Moreover, PPND negatively impacts on family functioning, on couples’ relationships, and on family members’ well-being. The aim of this paper is to present an overview of the current understandings on PPND and the potential screening, prevention, and treatment options.

The neural mechanisms and consequences of paternal caregiving

In recent decades, human sociocultural changes have increased the numbers of fathers that are involved in direct caregiving in Western societies. This trend has led to a resurgence of interest in understanding the mechanisms and effects of paternal care. Across the animal kingdom, paternal caregiving has been found to be a highly malleable phenomenon, presenting with great variability among and within species. The emergence of paternal behaviour in a male animal has been shown to be accompanied by substantial neural plasticity and to be shaped by previous and current caregiving experiences, maternal and infant stimuli and ecological conditions. Recent research has allowed us to gain a better understanding of the neural basis of mammalian paternal care, the genomic and circuit-level mechanisms underlying paternal behaviour and the ways in which the subcortical structures that support maternal caregiving have evolved into a global network of parental care. In addition, the behavioural, neural and molecular consequences of paternal caregiving for offspring are becoming increasingly apparent. Future cross-species research on the effects of absence of the father and the transmission of paternal influences across generations may allow research on the neuroscience of fatherhood to impact society at large in a number of important ways.

Family Matters: Rethinking the Psychology of Human Social Motivation

What motives do people prioritize in their social lives? Historically, social psychologists, especially those adopting an evolutionary perspective, have devoted a great deal of research attention to sexual attraction and romantic-partner choice (mate seeking). Research on long-term familial bonds (mate retention and kin care) has been less thoroughly connected to relevant comparative and evolutionary work on other species, and in the case of kin care, these bonds have been less well researched. Examining varied sources of data from 27 societies around the world, we found that people generally view familial motives as primary in importance and mate-seeking motives as relatively low in importance. Compared with other groups, college students, single people, and men place relatively higher emphasis on mate seeking, but even those samples rated kin-care motives as more important. Furthermore, motives linked to long-term familial bonds are positively associated with psychological well-being, but mate-seeking motives are associated with anxiety and depression. We address theoretical and empirical reasons why there has been extensive research on mate seeking and why people prioritize goals related to long-term familial bonds over mating goals. Reallocating relatively greater research effort toward long-term familial relationships would likely yield many interesting new findings relevant to everyday people’s highest social priorities.