Infanticide

=  Definition  =

Infanticide is the intentional murder of an infant. A relatively common practice among a variety of species, infanticide has been a recurring tendency throughout many human societies as well. Despite the disturbing nature of this topic, there are many theories and possible explanations for its occurrence:

Infanticide by Males
In harem-like species, in which groups of females are, in a sense, "dominated" by a single male, infanticide can be the result of a challenged male’s demise; in Hanuman langurs, as well as male lions, when the dominant male is defeated by a challenger, the challenger often kills the infants of the females, to replace them with his own offspring. This tactic also results in an increase in the females’ sexual receptivity, due to the absence of their offspring. One fourth of the deaths that occur among lion prides, in fact, are the result of infanticide (Lorenz, 1996). Male mice are infanticidal, then become paternal for about two months after having their own offspring, and then become infanticidal once again, in order to eliminate the potential future competitors of their offspring, thus increasing the fitness of the male and his pups. Paternal infanticide is not unheard of; male bass are very protective of their offspring up until the point at which the offspring are expected to swim away; any who don’t are typically eaten by the paternal male. This, infanticidal behavior among males not only reduces intraspecific competition between the incumbent's offspring and those of other males and increases the parental investment afforded to their own young, but also allows females to become sexually receptive sooner (since they are no longer preoccupied with taking care of their offspring) (Hausfater, 1948).

Infanticide by Females
While male infanticide can often be explained by the desire to dominate the group by killing its competitors’ offspring, while of course benefitting their own fitness, female infanticide is often considered to be a more common occurance. In many species, males are scarce in number, and in most species, scarce and selective in terms of parental investment. It is not a great surprise that females will commit infanticide to reduce not only future competition for their own offspring, but they often compete for parental investment on the part of the male (Williamson, 2000). In certain tropical bird species, the males often brood and tend to the nest while the females watch over territory; in an experiment in which the females were removed from their guarding positions, other females often attacked the chicks of the missing female. The males then abandoned the nest, as well as the original female, and mated with the competitor, producing eggs with her and tending to her offspring instead. Maternal infanticide is also not uncommon, especially among pigs and rabbits; in cases of maternal infanticide, it is often a demonstration of quality over quantity; by decreasing the mother’s brood, usually by killing the weakest individuals, she is therefore able to invest more attention in the rest of her offspring. Thus, female infanticidal behavior is typically a strategy by which to focus on the needs of their surviving offspring (Williamson, 2000).

Infanticide in Humans
Practiced among hundreds of human societies throughout history, infanticide is a relatively common occurrence in humans. While the practice of infanticide among other animal species seems to be predominantly a result of competition, whether among males, females, or the mother and the infant, the main causes of infanticide among humans are believed by historians to be economic reasons (Milner, 1998). Many human societies that practice infanticide end up favoring one sex over the other (most commonly males over females), in which case, the female child would be the most likely victim, in order for the parents to provide more resources for the surviving male child. Infanticide is also a tactic of population control, most notoriously practiced in China (an example of sex-based infanticide) (Milner, 1998). In Melanesian societies, female infanticide is very common, resulting in the ritualization of adolescent homosexuality, used as a sexual outlet prior to actual reproductive sex with females (Lorenz, 1996). Another aspect of infanticide that seems to be unique to humans is a more psychological element. Some psychologists attribute violence toward infants to the “displacement of certain emotions,” projected onto one's offspring. Postpartum psychosis is certainly a common cause of infanticide (Milner, 1998).

= Examples in Context =

In chapter two of Sexual Selections by Marlene Zuk, infanticide is discussed: in species such as the honeybee, female workers will sometimes manipulate the number of males or females they rear in the hive, and will even slip eggs of their own into the hive. Though not specifically infanticide, this strategy illustrates a major aspect of the tendency, which is the exploitation of the offspring of others in order to increase one’s own potential fitness (Zuk, 2003). David Barashprovides a theory of the possible roots of infanticide when he refers to parental altruism as “the glass half full,” as opposed to the idea of parent-offspring conflict; Barash, in an attempt to explain the relationship between parent and child in terms of self preservation, explains that “the infant is 100 percent related to itself and 50 percent related to its mother,” and vice versa, implying that once the infant stops being reliant on the parent, each will go on to value their own fitness over that of the other (Barash, 1980). In Barash’s The Whispering Within, Barash discusses a study by Richard Alexander which determined that more than half of 160 human societies practice (or once practiced) infanticide in the case of twins. In these scenarios, the infanticide is usually a matter of the mother being unable to provide for more than one child; rather than neglecting both children, one is killed. Barash discusses the ghastly occasion of an Australian society which sometimes kills one child to feed to the others, in extremely desperate situations (Barash, 1980). In From Here to Maternity, Sarah Hrdy discusses an experiment in which an infant rat was placed in the cage of a virgin female rat, who had never been exposed to an infant before. The experiment resulted in the female rat killing the infant, most likely the result of the rat simply not knowing what to do with it, having never seen the care of an infant before the experiment was conducted (Hrdy, 1999).

= History =

Infanticide has been a tactic of gender preference and population control for centuries, and the evidence dates back to ancient civilizations, such as Ancient Egypt, Pagan societies, European tribes, as well as Christianity during the Middle Ages, and since then has spread throughout the globe and touched every continent. Many major concepts of evolutionary biology, such as the very basic idea of pursuit of one's own genetic fitness via reproduction, have been challenged by the existence of infanticide, especially among animals and tribal societies.

= Debates =

While in the natural world, infanticide seems to be a more matter-of-fact technique to increase one’s own fitness and genetic success while decreasing that of another, the role of infanticide in human societies takes on an enormous amount of controversy. Being such a disturbing and sensitive subject, infanticide has consistently been the center of much moral and scientific debate. How can one justify killing an innocent infant before it is even given the chance to live? A recent moral debate is that over the situation in China. China’s one-child policy, established in the 1990’s, serves as a form of population control; urban couples are limited to one child per couple. This was first implemented in 1979, but was a policy that came about in 1978. Couples who violate this law are often fined greatly. Many families who cannot pay these fines tend to commit infanticide, or to simply abandon the unwanted child. The policy has, according to the United States State Department, as well as the Parliament of the United Kingdom, contributed greatly to infanticide, and the policy has caused a great deal of controversy and speculation (Milner, 1998). Another controversial topic involving infanticide is that of abortion, or the removal of a fetus from the womb; shaped by various scientific discoveries, abortion law has been an ever-changing subject of scientific and moral debate. Differences in opinion surrounding the point at which the fetus becomes “human,” the methods by which it is performed, and the idea of abortion in general have sparked up a storm of disagreement are often compared to infanticide (Milner, 1998).

= References =

1. Zuk, Marlene. Sexual Selections. Berkley, CA: University of California Press, 2003.

2. Barash, David P. The Whisperings Within: evolution and the origin of human nature. Harper &amp; Row, 1979; Penguin, 1980;

3. Williamson, Laila. " Infanticide: an anthropological analysis ". in Kohl, Marvin. Infanticide and the Value of Life. NY: Prometheus Books.

4. Hrdy, Sarah. Mother Nature: A history of mothers, infants and Natural Selection." New York: Pantheon, 1999.

5. Hrdy, Sarah. From Here to Materity . New York, NY: Knopf Double Day Publishing Group, 1999.

6. Lorenz, K. On Aggression. New York: Harcourt, Brace and World, 1996.

8. Hausfater, G. Infanticide: Comparative and Evolutionary Perspectives. Current Anthropology, 1948.

7. Milner, Larry S.. "www.infanticide.org". Society for Prevention of Infanticide. 1998. &lt;http://www.infanticide.org/history.htm&gt;.

= Author =

Nora Burke