Killing Babies: Hrdy on the Evolution of Infanticide (original) (raw)

Infanticide: Let's not throw out the baby with the bath water

Evolutionary Anthropology: Issues, News, and Reviews, 2005

RajasthaniIndia): Recent observations and a reconsideration of hypotheses. Primates 28:163-197. 15 Dolhinow P (in press) A mystery: Explaining behavior. In Strum SC, Lindburg DG, Hamburg DA (eds) The New Plzvsical Antlzro-16 Hrdy SB (1979) Infanticide among animals: A review, classification, and examination of the implications for the reproductivc strategies of females. Ethol Sociobiol 1:1340. 17 Hrdy SB (1984) Assumptions and evidence regarding the sexual selection hypothesis: a reply to Boggess. In Hausfater G, Hrdy SB (eds) Infanticide: Comparative and Evolutionaty Perspectives, pp. 315-319. New York: Aldine. 18 Newton PN (1988) The variable social organization of Hanuman langurs (Presbytis entellus). Infanticide and the monopolization of females. Int J Primatol 9:59-77. 19 Arnold S, Wade M (1 984) On the measure-pology. ment of natural selection: Theory. Evolution 38:709-719. 20 Phillips P, Arnold S (1989) Visualizing multivariate selection. Evolution 43: 1209-1 222. 21 Schluter D (1988) Estimating the form of natural selection on a quantitative trait. Evolution 45:849-861. 22

Infanticide as an evolutionarily stable strategy

Animal Behaviour, 1985

An evolutionarily stable strategies analysis of infanticide, expressed as two pure strategies, shows that the equilibrial frequency of infanticide depends on only two parameters: the relative advantage of infanticide when others are also infanticidal and the relative advantage of a non-infanticidal strategy if others are non-infanticidal. The possible equilibrial conditions of strictly infanticidal, strictly non-infanticidal, stably polymorphic or history-dependent populations correspond to various earlier models of infanticide. Thus, these earlier models may be subsumed as special cases of the ESS analysis. This permits the comparison of alternative theories of infanticide in specific cases of infanticide in natural populations. In particular, it is argued that if infanticide confers a relative advantage on the perpetrator when other population members are non-infanticidal, this is sufficient to reject a 'maladaptive' explanation for infanticide. The potential existence of history-dependent equilibria suggests there will be extreme difficulty with non-experimental methods that attempt to test the adaptiveness of infanticidal behaviour.

A New Explanation of Female Infanticide from the Sexual Selection Point

Academia Letters, 2022

The idea of female infanticide fall in the scope of my academic interest when a friend sent me her, by that time unpublished article[1]. This text told about the tradition of female infanticide in Svaneti, in the mountainous region of northern Georgia. Running small research on tradition, described in the text, I have found Svan origin sources, who still remember that. Moreover, according to them, this tradition was maintained in Svaneti until the 30-es of the twentieth century. Usually, according to the sources, newborn girl were put ashes into their nose and mouth to shut down her airways. The newborn was dying almost instantly. The name of this action was "feeding with ashes". This description differs from the references from the 19th century, according to which the Svans practicing female infanticide by putting burning coals in the mouth of newborn girls[2]. Clearly, stopping breathing with ash is both more humane and less brutal. Existence of this mind-breaking description (use of burning coal) in the 19th century sources can be explained for two reasons: 1. a misunderstood of the explanation from locals; 2. The Russian imperial attempt to describe the conquered locals (in this case the Svans) as savages as possible. Short history It is well known that infanticide, like cannibalism, is a universal phenomenon and has no exceptions in the history of peoples and continents[3]. The search for the social causes of

Mothers who kill evolutionary underpinnings

Women who kill their children present a profound challenge to accepted notions of motherhood and the protection offered by mothers to their children. Historically, societies have varied in the sanctions applied to perpetrators of such acts, across both time and place. Where penalties were once severe and punitive for mothers, in modern times some two dozen nations now have infanticide acts that reduce the penalties for mothers who kill their infants. Embedded within these acts are key criteria that relate (a) only to women who are (b) suffering the hormonal or mood effects of pregnancy/lactation at the time of the offence which is (c) usually restricted to within the first year after delivery. Criticisms of infanticide legislation have largely centered on inherent gender bias, misconceptions about the hormonal basis of postpartum psychiatric disorders, and the nexus and contribution of these disorders to the offending in relation to issues of culpability and sentencing. Important differences between female perpetrators relative to the age of the child victim have also highlighted problems in the implementation of infanticide legislation. For example, women who commit neonaticide (murder during the first day of life) differ substantially from mentally ill mothers who kill older children. However, despite these shortcomings, many nations have in recent years chosen to retain their infanticide acts. This article reviews the central controversies of infanticide legislation in relation to current research and fundamental fairness. Using evolutionary psychology as a theoretical framework to organize this discussion, it is argued that infanticide legislation is at best unnecessary and at worst misapplied, in that it exculpates criminal intent and fails to serve those for whom an infanticide defense might otherwise have been intended.

On the evolutionary stability of female infanticide

Behavioral Ecology and Sociobiology, 1997

Territoriality among female rodents may have evolved as an adaptation to intraspeci®c competition for resources or, alternatively, to defend pups against infanticide. In order to evaluate the latter, we analyse the conditions that allow an infanticidal strategy to invade a population of non-infanticidal females, and the circumstances under which infanticide may become an evolutionarily stable strategy (ESS). Our game theoretical analyses indicate that infanticide has to be associated with some direct (cannibalism) or indirect (reduced competition) resource bene®ts in order to invade a non-infanticidal population. We also expect that females will primarily kill litters of nearby neighbors, thereby removing the closest competitors while keeping costs at a low level. However, once established in a population, infanticide may be an ESS, even if females do not gain any resource bene®ts. This is theoretically possible if a female through infanticide can reduce the possibility that other, potentially infanticidal, females establish and/or stay close to her nest. While behavioral data indicate that these special circumstances sometimes occur, they may be too speci®c to apply generally to small rodents. Therefore, we expect that the evolutionary stability of infanticide often requires resource bene®ts, and that female infanticide in small rodents may, in fact, be a consequence rather than a cause of territoriality.

Mothers who kill their offspring: Testing evolutionary hypothesis in a 110-case Italian sample

Child Abuse & Neglect, 2012

Objectives: This research aimed to identify incidents of mothers in Italy killing their own children and to test an adaptive evolutionary hypothesis to explain their occurrence. Methods: 110 cases of mothers killing 123 of their own offspring from 1976 to 2010 were analyzed. Each case was classified using 13 dichotomic variables. Descriptive statistics and hierarchical cluster analysis were performed both for cases and variables, and significant differences between clusters were analyzed. Results: The Italian sample of neonaticides (killings of children within the first day of life) was found to satisfy all evolutionary predictions for an evolved behavioral, emotional and motivational pattern to increase fitness, showing a consistent profile for offending mothers. Relatively young, poor women with no partner kill their offspring non-violently, either directly or through abandonment, and they attempt to conceal the body. These women have no psychopathologies and never attempt suicide after killing their children. All neonaticide cases fall in a single cluster that is distinct from all other offspring killings by mothers. Infanticide (killing of children within the first year of life) and filicide (killing of children after the first year of life) do not significantly differ according to any of the variables measured. The common profile of mothers who have committed infanticide or filicide includes psychopathology, suicide or attempted suicide after killing their children, violent killing of their victims, and no attempt to conceal the victims' bodies. These results suggest that maternal infanticide and filicide represent an improper functioning of adaptation, and their profile are much more variable than those of neonaticide offenders. Conclusion: Our study confirms that only neonaticide is an adaptive reproductive disinvestment, possibly evolved in the remote past, to increase the biological fitness of the mother by eliminating an unwanted newborn and saving resources for future offspring born in better conditions. Neonaticide is shown to be clearly distinct from infanticide and filicide and therefore should be approached, prevented, and judged differently.

Infant killing as an evolutionary strategy: Reality or myth?

Evolutionary Anthropology, 2005

The students nodded. They had all studied animal behavior, and they knew, for example, that when a new male took over a lion pride, the first thing he did was kill all the cubs. The reason was apparently genetic: the male had evolved to disseminate his genes as widely as possible, and by killing the cubs he brought all the females into heat, so that he could impregnate them.

Routine Infanticide in the West 1500-1800

History Compass, 2016

Historians have assumed that early modern Europeans did not practice neo-naticide similar to the great Asian civilizations, but sex-ratio studies are only now entering the demographic literature. This article passes in review both published and unpublished research on sex ratios at baptism in Italy, France, England and colonial Acadia, together with juvenile sex ratios drawn from censuses in Germany, France and Italy. Both endemic and conjunctural imbalances appear everywhere, but they could target females or males depending upon the context. It is still considered newsworthy that in much of the world, parents select the sex of their children before bringing a pregnancy to term. In China, the sex ratio at birth is currently 116 males for every female, while in India, the rate is 111, significantly above the well-established biological norm of 105. 1 This sex preference creates well-publicized difficulties for young men seeking brides (The Economist, April 18 2015). Why kill females preferentially? The literature often lays the blame on misogynistic ideologies, suggesting that it would be sufficient to combat them with propaganda in order to eradicate the practice. There are several better reasons: first of all, in agricultural economies requiring strenuous ploughing with large animals and equally strenuous field and forest work far from home, males were better value. In patrilocal societies where husbands, or their families, received a sizeable dowry for the bride (which served as a security cushion for her and her children in the event of the premature death of either spouse), parents were unequal to the task of providing those for several daughters. Finally, if the aim is to keep the future population stable in order not to overstretch resources, then killing future child-bearers is simply more efficient than killing males and females indiscriminately. Today unwanted pregnancies are usually terminated by abortion, but in the past, the safer solution was to kill the newborn or expose it to the elements. Infanticide, like abortion, may be human universals, that is, part of the behavioural repertoire of every known society, although its frequency would vary according to local environmental conditions. 2 Humans are not alone in this behaviour: mothers in many species of mammals will sometimes cull their offspring at birth. In Darwinian language, infanticide, or abortion that has replaced it, are adaptive mechanisms involving some kind of rational decision-making on the part of the parent, which is usually the mother. 3 In most societies, newborns are not considered full-f ledged persons when leaving the womb. Rather, some sort of ceremony confers a name and social identity on them, sometimes providing an additional set of symbolic kin. Returning to the great Asian civilizations where sex-selective behaviour persists, parents enact strategies to better themselves and assess the likelihood of survival and future of the newborn infant. In traditional China and Japan, neonatal infanticide was a kind of post-natal abortion that allowed parents to choose the number, the spacing and the sex of their offspring, while coping better with short-term difficulties like famine. 4 In his compelling recent study on northeastern Japan, Fabian Drixler suggests that one-third of live births ended with infanticide during the 18th century, despite government disapproval of the practice. 5 Historians sometimes