Although the abortion of fetuses with Down syndrome has become commonplace, infanticide is still widely rejected. Generally, there are three ways of justifying the differentiation between abortion and infanticide: by referring to the differences between the moral status of the fetus versus the infant, by referring to the differences of the moral status of the act of abortion versus the act of i...

Infanticide can be a major influence upon the social structure of species in which females maintain long-term associations with males. Previous studies have suggested that female mountain gorillas benefit from residing in multimale groups because infanticide occurs when one-male groups disintegrate after the dominant male dies. Here we measure the impact of infanticide on the reproductive succe...

BACKGROUND Infanticide by adult male occurs in many mammalian species under natural conditions, and it is often assumed to be a goal-directed action and explained predominately by sexual selection. Motivation of this behavior in mammals is limitedly involved. METHODOLOGY AND PRINCIPAL FINDINGS We used long-term reproductive records and direct observation in captivity and in the field of two s...

Infanticide has recently been observed in several primate species while female counterstrategies are seemingly rare. The question of why mothers do not increase their resistance to infanticide is investigated using a haploid two-locus model. A hypothesis that mothers can recover lost offspring by gaining more grandchildren is rejected in most cases, and it is shown that costs and benefits for b...

OBJECTIVE Although maternal infanticide is a rare event, a high proportion of cases occurs in the context of postpartum mental illness. The author reviews historical, legislative, and contemporary psychiatric perspectives on infanticide and discusses ways in which the psychiatric community can improve prevention of infanticide and promote appropriate treatment of mentally ill women who commit i...

One of the earliest recognized forms of sexual conflict was infanticide by males, which imposes serious costs on female reproductive success. Here I review two bodies of evidence addressing coevolved strategies of males and females. The original sexual selection hypothesis arguing that infanticide improves male mating success by accelerating the return of females to fertilizable condition has b...

We report the first case of directly observed infanticide in the Alpine marmot (Marmota marmota). Moreover, previous and present observations suggest that 12 young could have been killed by infanticide in the population under study. The bodies of five of them were found with similar neck injuries. In all cases, infanticidal animals were adult males entering a territory in the absence of the res...

I if When I visited the hospital I knew that the birth had taken place about a week before, so I went prepared to see an almost completely recovered young mother, to admire the baby and chat hilariously about the shocks and indignities of the labour ward. It was normal visiting hours so it did not occur to me to ask a nurse if I could see her. Knowing the number of her room, I went straight up ...

Killing conspecific infants (infanticide) is among the most puzzling phenomena in nature. Stable polymorphism in such behaviour could be maintained by negative frequency-dependent selection (benefit of rare types). However, it is currently unknown whether there is genetic polymorphism in infanticidal behaviour or whether infanticide may have any fitness advantages when rare. Here we show geneti...