Sexually Dimorphic Control of Parenting Behavior by the Medial Amygdala.

Social behaviors, including behaviors directed toward young offspring, exhibit striking sex differences. Understanding how these sexually dimorphic behaviors are regulated at the level of circuits and transcriptomes will provide insights into neural mechanisms of sex-specific behaviors. Here, we uncover a sexually dimorphic role of the medial amygdala (MeA) in governing parental and infanticidal behaviors. Contrary to traditional views, activation of GABAergic neurons in the MeA promotes parental behavior in females, while activation of this population in males differentially promotes parental versus infanticidal behavior in an activity-level-dependent manner. Through single-cell transcriptomic analysis, we found that molecular sex differences in the MeA are specifically represented in GABAergic neurons. Collectively, these results establish crucial roles for the MeA as a key node in the neural circuitry underlying pup-directed behaviors and provide important insight into the connection between sex differences across transcriptomes, cells, and circuits in regulating sexually dimorphic behavior.

Multisensory Logic of Infant-Directed Aggression by Males.

Newborn mice emit signals that promote parenting from mothers and fathers but trigger aggressive responses from virgin males. Although pup-directed attacks by males require vomeronasal function, the specific infant cues that elicit this behavior are unknown. We developed a behavioral paradigm based on reconstituted pup cues and showed that discrete infant morphological features combined with salivary chemosignals elicit robust male aggression. Seven vomeronasal receptors were identified based on infant-mediated activity, and the involvement of two receptors, Vmn2r65 and Vmn2r88, in infant-directed aggression was demonstrated by genetic deletion. Using the activation of these receptors as readouts for biochemical fractionation, we isolated two pheromonal compounds, the submandibular gland protein C and hemoglobins. Unexpectedly, none of the identified vomeronasal receptors and associated cues were specific to pups. Thus, infant-mediated aggression by virgin males relies on the recognition of pup's physical traits in addition to parental and infant chemical cues.

Eviction-driven infanticide and sexually selected adoption and infanticide in a neotropical parrot.

Infanticide and adoption have been attributed to sexual selection, where an individual later reproduces with the parent whose offspring it killed or adopted. While sexually selected infanticide is well known, evidence for sexually selected adoption is anecdotal. We report on both behaviors at 346 nests over 27 y in green-rumped parrotlets (Forpus passerinus) in Venezuela. Parrotlets are monogamous with long-term pair bonds, exhibit a strongly male-biased adult sex ratio, and nest in cavities that are in short supply, creating intense competition for nest sites and mates. Infanticide attacks occurred at 256 nests in two distinct contexts: 1) Attacks were primarily committed by nonbreeding pairs (69%) attempting to evict parents from the cavity. Infanticide attacks per nest were positively correlated with population size and evicting pairs never adopted abandoned offspring. Competition for limited nest sites was a primary cause of eviction-driven infanticide, and 2) attacks occurred less frequently at nests where one mate died (31%), was perpetrated primarily by stepparents of both sexes, and was independent of population size. Thus, within a single species and mating system, infanticide occurred in multiple contexts due to multiple drivers. Nevertheless, 48% of stepparents of both sexes adopted offspring, and another 23% of stepfathers exhibited both infanticide and long-term care. Stepfathers were often young males who subsequently nested with widows, reaching earlier ages of first breeding than competitors and demonstrating sexually selected adoption. Adoption and infanticide conferred similar fitness benefits to stepfathers and appeared to be equivalent strategies driven by limited breeding opportunities, male-biased sex ratios, and long-term monogamy.

Counter-strategies to infanticide: The importance of cubs in determining lion habitat selection and social interactions.

Animal social and spatial behaviours are inextricably linked. Animal movements are driven by environmental factors and social interactions. Habitat structure and changing patterns of animal space use can also shape social interactions. Animals adjust their social and spatial behaviours to reduce the risk of offspring mortality. In territorial infanticidal species, two strategies are possible for males: they can stay close to offspring to protect them against rivals (infant-defence hypothesis) or patrol the territory more intensively to prevent rival intrusions (territorial-defence hypothesis). Here, we tested these hypotheses in African lions (Panthera leo) by investigating how males and females adjust their social and spatial behaviours in the presence of offspring. We combined datasets on the demography and movement of lions, collected between 2002 and 2016 in Hwange National Park (Zimbabwe), to document the presence of cubs (field observations) and the simultaneous movements of groupmates and competitors (GPS tracking). We showed a spatial response of lions to the presence of offspring, with females with cubs less likely to select areas close to waterholes or in the periphery of the territory than females without cubs. In contrast, these areas were more selected by males when there were cubs in the pride. We also found social responses. Males spent more time with females as habitat openness increased but the presence of cubs in the pride did not influence the average likelihood of observing males with females. Furthermore, rival males relocated further after an encounter with pride males when cubs were present in the prides, suggesting that the presence of cubs leads to a more vigorous repulsion of competitors. Males with cubs in their pride were more likely to interact with male competitors on the edge of the pride's home range and far from the waterholes, suggesting that they are particularly assiduous in detecting and repelling rival males during these periods. In general, the strategies to avoid infanticide exhibited by male lions supported the territorial-defence hypothesis. Our study contributes to answer the recent call for a behavioural ecology at the spatial-social interface.

The criminalization of women with postpartum psychosis: "a call for action" for judicial change.

PURPOSE: To prevent the incarceration and influence outcomes when criminal culpability is linked to postpartum psychosis. METHODS: Infanticide, neonaticide and filicide are most often linked with postpartum psychosis, which affects 1-2 women per 1,000 births or 4,000 women each year in the United States. Multiple genetic, hormonal and psychosocial factors surrounding childbirth result in a 1 to 4% risk of infanticide in women with postpartum psychosis. The authors seek to increase awareness of postpartum psychosis and postpartum depression in state legislatures. Others are working to have it recognized in the Diagnostic and Statistical Manual of Mental Disorders (DSM) as a specific illness. Specific postpartum legislation for those charged with crimes related to maternal mental illness is necessary. RESULTS: In Illinois, the very first criminal law in the nation recognizing the pernicious effects of this illness went into effect in 2018. The authors and others are attempting to cause similar or broader legislation to be brought in other states. Several women have been released from extended incarceration utilizing this law. CONCLUSIONS: This temporary mental illness can lead to tragic outcomes when hospitalization and crisis intervention is delayed or the illness is misdiagnosed. The legal/judicial system has not utilized the growing body of scientific developments that medical researchers have discovered in recent decades. The lack of a unique diagnostic classification in the DSM and the lack of postpartum criminal laws, lead to mentally ill mothers in the U.S. receiving excessively harsh sentences when prosecuted, evidenced both in trial and sentencing.

Domestic violence as a risk factor of maternal filicide.

PURPOSE: This paper will investigate precursors to maternal filicide, focusing on domestic violence. While psychosis is often well described, less frequently explored are the connections between prior trauma, domestic violence, depression, and filicide. We will discuss reasons why a woman may not disclose domestic violence and suggest possible areas for intervention. METHODS: We present a case involving domestic violence, its impact on mental health, and eventual filicide. We then present an alternative scenario of the same case where filicide is considered, but is avoided. RESULTS: The case of the mother who experienced domestic violence and was accused and sentenced for filicide is seen in greater relief by presenting the case in an alternative scenario with effective interventions. It is clear the availability and the ability to access community supports, such as obstetric and pediatric screening, psychiatric treatment, domestic violence shelters, intimate partner violence outreach services, parenting support groups, and hospital social work case management, tragedies such as filicide can be prevented. CONCLUSION: Traumatic early childhood experiences predispose people to a stress-response system that is more prone to inactivity and impulsivity. This can cause women in domestic violence relationships to stay, limit their options for family planning, become increasingly depressed, not seek community support, and risk impulsive action of harming their child. This risk can be mitigated by building stable relationships with their medical team, treating depression, connecting with home visitation programs, and being empowered to access contraception.

Filicide in Africa: a systematic review.

BACKGROUND: Filicide, the act of a parent or parental figure killing their child, has been reported in various African countries. However, there is a lack of comprehensive reviews on the prevalence and associated factors of filicide across the African continent, which is characterized by diverse cultural beliefs and practices. This review aims to examine the prevalence and risk factors of filicide in Africa. METHODS: This review included studies on filicide in Africa, identified through searches in various databases (PubMed, Scopus, Africa Journal Online, and Google Scholar) using relevant keywords. The Mendeley reference manager was used to organize all identified articles and remove duplicate entries. A two-round screening process was conducted by two independent reviewers, with the final set of articles selected through mutual agreement. The quality of the studies was then assessed. RESULTS: Out of the 107 retrieved articles, only 15 were included in the review. These studies revealed diverse prevalence rates: 3.7% of total homicides, 1.38% of deaths from family violence, and 13.02% for autopsied children. Various potential risk factors for filicide were identified, including unwanted pregnancies, marital conflicts, family disputes and violence, low socio-economic status, mental health issues in perpetrators, and mental, physical, or neurological vulnerabilities in victims. Cultural beliefs were also recognized as contributing factors to filicide. CONCLUSION: Filicide is a complex and multi-dimensional issue influenced by various individual, familial, and societal factors. The review highlighted a high prevalence of filicide in Africa, shaped by these diverse factors.

Intergroup encounters in pair-living primates: Comparative analysis and a case study of pair-living and monogamous owl monkeys (Aotus azarae) of Argentina.

The function of intergroup encounters (IGEs) may differ substantially among species of different group sizes and social organizations. Research in group-living primates has shown that the behavioral responses during IGEs can vary widely from affiliative to neutral or aggressive interactions; still, little is known about IGEs in pair-living taxa. We conducted a systematic literature review to find relevant studies on the functions of IGEs in pair-living nonhuman primates that could inform analyses of IGE data (n = 242 IGEs, 21 groups and 10 solitary individuals, 1997-2020) from wild owl monkeys, a pair-living, monogamous primate with extensive biparental care. We identified 1315 studies published between 1965 and 2021; only 13 of them (n = 10 species) contained raw data on the number of IGEs. Our review of those studies showed that IGEs are common, but highly variable in their nature and characteristics in pair-living primates. To examine the non-mutually exclusive hypotheses of resource-, and mate defense, and infanticide avoidance we analyzed data from the Owl Monkey Project 27-year long database to build first an a priori model set. To incorporate prior knowledge from the literature review, we conducted our analyses as a consecutive series of binomial logistic regressions. All IGEs including all biologically relevant parameters (N = 156) were codified into three different behavioral categories (Reaction, Agonism, and Physical Aggression). The analysis showed that owl monkeys regularly engaged in IGEs, most of which were agonistic. They showed more reaction when infants were present, but reactions were less physically aggressive when infants and pregnant females were involved. Overall, our results lend more support for the infant and mate defense hypotheses than they do for the resource defense one.

Early Filial Cannibalism in Fish Revisited: Endocrinological Constraint, Costs of Parental Care, and Mating Possibility.

AbstractOffspring desertion by parents generally occurs at an early stage of parental care, which is thought to minimize the costs of parental care prior to desertion. This study investigated the effects of endocrinological constraints on early total filial cannibalism by male Rhabdoblennius nitidus in the field, a paternal brooding blennid fish with androgen-dependent brood cycling. In brood reduction experiments, cannibal males showed low levels of plasma 11-ketotestosterone (11-KT) relative to noncannibals and also similar levels of 11-KT to males in the parental care phase. Since 11-KT regulates male courtship intensity, males with decreased courtship activity would exhibit total filial cannibalism. However, there is a possibility that a transient increase in 11-KT levels at the early stage of parental care delays total filial cannibalism. In contrast, total filial cannibalism could occur before a decline to the lowest 11-KT levels, at which point males might still be able to exhibit courtships, possibly to reduce the costs of parental care. To understand how much and when caregiving males exhibit mating and parental care behaviors, it is important to consider not only the presence of endocrinological constraints but also its intensity and flexibility.

Diverse strategies that animals use to deter intraspecific predation.

Intraspecific predation is a special case of prey-predator system that is taxonomically widespread. While a heterospecific predator's main goal is to achieve nutrition, intraspecific predation provides conspecifics with other benefits including elimination of competitors for resources and mates. Traditionally intraspecific predation is termed based on the context they occur within, for example egg cannibalism, infanticide and sexual cannibalism. These diverse forms of intraspecific predation and the strategies by which animals are known to deter them are summarized categorically in this review. The diversity of defence strategies animals deploy against conspecific predators is appreciable and raises interesting questions on their evolution for future research.

Why there is no dilemma for the birth strategy: a response to Bobier and Omelianchuk.

Bobier and Omelianchuk argue that the Birth Strategy for addressing analogies between abortion and infanticide is saddled with a dilemma. It must be accepted that non-therapeutic late-term abortions are either, impermissible, or they are not. If accepted, then the Birth Strategy is undermined. If not, then the highly unintuitive claim that non-therapeutic late-term abortions are permissible must be accepted. I argue that the moral principle employed to defend the claim that non-therapeutic late-term abortions are morally impermissible fails to do so. Furthermore, the principle that people have a right to bodily autonomy can be used as an argument for the conclusion that non-therapeutic late-term abortions are permissible and is intuitively stronger than the intuition for the opposite of this conclusion. This is because people having a right to bodily autonomy explains the impermissibility of rape and sexual assault. Consequently, the posited dilemma is defused and does not undermine the Birth Strategy.

Egalitarianism, moral status and abortion: a reply to Miller.

Calum Miller recently argued that a commitment to a very modest form of egalitarianism-equality between non-disabled human adults-implies fetal personhood. Miller claims that the most plausible basis for human equality is in being human-an attribute which fetuses have-therefore, abortion is likely to be morally wrong. In this paper, I offer a plausible defence for the view that equality between non-disabled human adults does not imply fetal personhood. I also offer a challenge for Miller's view.

Orphans cannot be after-birth aborted: a response to Bobier.

I offer a response to an objection to my account of the moral difference between fetuses and newborns, an account that seeks to address an analogy between abortion and infanticide, which is based on the apparent equality of moral value of fetuses and newborns.

A case-control study of filicide/infanticide in 90 mothers.

This study aims to explore the clinical and socio-demographic characteristics of 30 women who committed filicide and compare them to those of 60 postpartum women who did not commit filicide, including 30 with severe postpartum mental illness and 30 without a known history of psychiatric disorders. Clinical assessment included a face-to-face interview with the Structured Clinical Interviews for DSM-IV Axis I and Axis II Disorders. Information on socio-economic, medical, and personal factors was collected using the Clinical Interview for DSM-IV and organized in a clinical vignette and OPCRIT ratings. Consensus best-estimate diagnoses were made according to DSM-V criteria. Inference was conducted using Fisher's exact test for categorical variables and Mann-Whitney U rank test for continuous variables. Family history of violent death, psychotic symptoms (OR 8.3; CI 95% 2.26-36.13), severe insomnia (9.8; 2.28-61.75), and a schizophrenia spectrum or bipolar diathesis (4.8; 1.22-23.86) were associated with history of filicide. Rates of history of sexual abuse in childhood were higher in both the filicide and the severe postpartum mental illness groups compared to healthy controls (6.7; 1.25-70.46 and 7.8; 1.47; 80.47 respectively). Conversely, we did not observe any difference in the rates of history of sexual abuse in adulthood across groups. The lack of adequate postpartum psychiatric care was an important precipitating factor in many cases of infanticide and even late filicide. This study underscores the need for increasing awareness by health care professionals and the wider society of the complex dynamics and psychiatric risks associated with motherhood.

Filicide by mentally ill maternal perpetrators: a longitudinal, retrospective study over 30 years in a single Northern Italy psychiatric-forensic facility.

Characterization of mentally ill maternal perpetrators of filicide assigned to a single psychiatric-forensic facility, including previous access to mental health services. A cross-sectional, retrospective analysis of medical records and legal documentation of maternal filicide patients at a single psychiatric-forensic facility (1990-2021) was performed. Socio-demographic, relationship, psychopathological, and criminological characteristics were collected. Data were compared according to previous perpetrators' access to mental health services or not and access within 1 year prior to filicide or not. All 55 detainees (mean age 34.8 ± 6.2 years) were included. There were 64 victims; 15 (23%) were ≤ 1 year old and most (77%) were single victims. Some mothers had history of violence/abuse (29%), an aggressive parent (45%), and violent relationships with their intimate partner (46%) and were socially isolated (49%). Most crimes were motivated by altruism (53%). Women had attempted suicide in 39% of filicide cases. Previous psychiatric diagnoses were available for 56%; 71% had accessed services for ≤ 1 year. Patients unknown to mental health services were less likely Italian, with children below preschool age and with no history of physical abuse/violence, aggressive parent, or suicide attempts. Patients lost to mental health services (> 1 year) were less likely Italian or assuming psychopharmacological therapy, were in shorter relationships, and were mostly diagnosed with personality disorders. Female perpetrators of filicide are often unknown/lost to mental health services prior to the crime. Multifactorial historical and current characteristics aid in identifying mothers at risk. Communication of the availability of mental health services must be multi-lingual.

Mother-offspring proximity maintenance as an infanticide avoidance strategy in bornean orangutans (Pongo pygmaeus wurmbii).

Sexually-selected infanticide by males is widespread across primates. Maternal protection is one of many infanticide avoidance strategies employed by female primates. Bornean orangutan (Pongo pygmaeus wurmbii) mothers with younger offspring are less social with males than mothers with older offspring. Additionally, the distance between a mother and offspring decreases in the presence of male conspecifics, but not female conspecifics. We hypothesized that mothers are responsible for the change in mother-offspring proximity when males are present. Using a year of behavioral data from orangutans in Gunung Palung National Park, we tested whether the Hinde Index, a ratio of the number of approaches and leaves between two individuals, was indicative of mother or offspring proximity maintenance across different social groupings. The semi-solitary social organization of orangutans allows us to observe different social groupings. We found that the mother-offspring Hinde Index was typically indicative of offspring maintenance of proximity. However, the presence of male conspecifics was associated with an increase in the Hinde Index which indicates that mothers are responsible for the decrease in mother-offspring distance when males are present. The decrease in mother-offspring distances and increase in Hinde Index when males are present indicates that mothers react to the presence of males in a protective manner. We suggest this may be an infanticide avoidance behavior by mother orangutans.

States of Mind with Respect to Attachment: a comparative study between women who killed their children and mothers diagnosed with post-partum depression.

INTRODUCTION: Attachment theory has been linked with the caregiving system, acting as a drive for a mother's behavior towards her offspring. The most dramatic consequence of distress following maternity is filicide. Despite this, only few studies addressed the attachment models of women who committed filicide, and very little provided comparisons with mothers diagnosed with post-partum depression. OBJECTIVE: We described the socio-demographic and psychopathological characteristics of mothers who committed filicide. Our aim was to detect differences in the attachment models between mothers who committed filicide, mothers with post-partum depression and control mothers. Participants and setting: We recruited 19 women who committed filicide (group F) along with 52 women with post-partum depression (group D), and 23 control mothers (group C). METHODS: We administered a semi-structured interview on socio-demographic aspects and psychiatric history along with the Adult Attachment Interview. We performed an ANOVA, a post-hoc analysis and a logistic regression. RESULTS: The logistic regression showed a higher prevalence of Dismissing and Disorganized attachments in women of group F compared with group C (p = 0.002, p = 0.007). Dismissing attachment was also overrepresented in group D vs group C (p = 0.012). Interestingly, women of group F showed a Preoccupied/entangled attachment to a lesser extent than those of group D, reaching a borderline significance (p = 0.056). CONCLUSIONS: Disorganized and Dismissing models of attachment are prevalent in women who committed filicide compared with mothers with post-partum depression and controls, while other models of attachment are less frequent. Therefore, attachment could be taken into consideration to define the risk for committing filicide.

Involvement of Serotonergic Projections from the Dorsal Raphe to the Medial Preoptic Area in the Regulation of the Pup-Directed Paternal Response of Male Mandarin Voles.

Male mammals display different paternal responses to pups, either attacking or killing the young offspring, or contrastingly, caring for them. The neural circuit mechanism underlying the between-individual variation in the pup-directed responsiveness of male mammals remains unclear. Monogamous mandarin voles were used to complete the present study. The male individuals were identified as paternal and infanticidal voles, according their behavioral responses to pups. It was found that the serotonin release in the medial preoptic area (MPOA), as well as the serotonergic neuron activity, significantly increased upon licking the pups, but showed no changes after attacking the pups, as revealed by the in vivo fiber photometry of the fluorescence signal from the 5-HT 1.0 sensor and the calcium imaging indicator, respectively. It was verified that the 5-HTergic neural projections to the MPOA originated mainly from the ventral part of the dorsal raphe (vDR). Furthermore, the chemogenetic inhibition of serotonergic projections from the vDR to the MPOA decreased the paternal behaviors and shortened the latency to attack the pups. In contrast, the activation of serotonergic neurons via optogenetics extended the licking duration and inhibited infanticide. Collectively, these results elucidate that the serotonergic projections from the vDR to the MPOA, a previously unrecognized pathway, regulate the paternal responses of virgin male mandarin voles to pups.

Monstrous Mothering: Understanding the Causes of and Responses to Infanticide.

The deliberate killing of a child by its mother is abhorrent and is associated in the minds of many with mental illness and in particular with postnatal depression. However, at least 50% of perpetrators are neither "mad" nor "bad", and mothers who kill children are not "unhinged" by pregnancy or childbirth. We propose a different explanation: "blind rage" or "overwhelmed syndrome", whereby parents, stressed to breaking point by sleep deprivation or incessant baby crying, respond by lethally harming their child contrary to previous behaviour. The roots of this blind rage may be found in psychosocial disturbances, including the mother's own unsatisfactory experience of parenting which has caused attachment disorders. The legal framework guiding decisions to prosecute and structuring sentencing decision-making following conviction should acknowledge the exceptional stress experienced by such mothers postnatally. Health professionals including midwives and obstetricians should increase their vigilance and arrange referrals for mothers at risk of causing harm or committing infanticide.

A retrospective view of early research on dominance, stress and reproduction in cooperatively breeding carnivores.

Social carnivores have been central in studies of cooperative breeding, and research using noninvasive methods to examine behavioral and endocrine mechanisms of reproductive suppression started in the 1980s with dwarf mongooses in Serengeti National Park. Here, I synthesize the methods, findings and limitations of a research program that examined relationships between social dominance, age, mass, aggression, mating, gonadal steroids, glucocorticoids and reproduction in female and male dwarf mongooses, African wild dogs and wolves. Infanticide is a reliable backstop for reproductive suppression in females, and reproduction is energetically costly in these species. These conditions favor hypothalamic - pituitary - gonadal (HPG) adaptations that reduce the fertility of subordinate females to avoid the cost of producing doomed offspring. Infanticide also favors close synchronization of reproduction when subordinate females do become pregnant. In males, infanticide is a less reliable backstop and reproduction is less costly, so direct effects of subordination on fertility are less pronounced. Age is a strong predictor of social dominance in these species, but the evolutionary reason for this is not clear. In dwarf mongooses and wild dogs, alpha females were never deposed by younger packmates, but alpha males were: this difference is also not understood. Patterns of reproduction supported models predicting that alphas are less likely to share reproduction when the fitness costs of reproduction are high, when the fitness expected for dispersers is low, and with young subordinates to whom they are more closely related. Correlations between dominance and adrenal glucocorticoid concentrations varied between species and sexes, but did not support the hypothesis that chronic stress causes reproductive suppression.