By Steven Pinker
Two cases have recently riveted the American public. Last November, Amy Grossberg and Brian Peterson, 18-year-old college sweethearts, delivered their baby in a motel room and, according to prosecutors, killed him and left his body in a Dumpster. They will go on trial for murder next year and, if convicted, could be sentenced to death. In June, another 18-year-old, Melissa Drexler, arrived at her high-school prom, locked herself in a bathroom stall, gave birth to a boy and left him dead in a garbage can. Everyone knows what happened next: she touched herself up and returned to the dance floor. In September, a grand jury indicted her for murder.
How could they do it? Nothing melts the heart like a helpless baby. Even a biologist's cold calculations tell us that nurturing an offspring that carries our genes is the whole point of our existence. Neonaticide, many think, could be only a product of pathology. The psychiatrists uncover childhood trauma. The defense lawyers argue temporary psychosis. The pundits blame a throwaway society, permissive sex education and, of course, rock lyrics.
But it's hard to maintain that neonaticide is an illness when we learn that it has been practiced and accepted in most cultures throughout history. And that neonaticidal women do not commonly show signs of psychopathology. In a classic 1970 study of statistics of child killing, a psychiatrist, Phillip Resnick, found that mothers who kill their older children are frequently psychotic, depressed or suicidal, but mothers who kill their newborns are usually not. (It was this difference that led Resnick to argue that the category infanticide be split into neonaticide, the killing of a baby on the day of its birth, and filicide, the killing of a child older than one day. )
Killing a baby is an immoral act, and we often express our outrage at the immoral by calling it a sickness. But normal human motives are not always moral, and neonaticide does not have to be a product of malfunctioning neural circuitry or a dysfunctional upbringing. We can try to understand what would lead a mother to kill her newborn, remembering that to understand is not necessarily to forgive.
Martin Daly and Margo Wilson, both psychologists, argue that a capacity for neonaticide is built into the biological design of our parental emotions. Mammals are extreme among animals in the amount of time, energy and food they invest in their young, and humans are extreme among mammals. Parental investment is a limited resource, and mammalian mothers must ''decide'' whether to allot it to their newborn or to their current and future offspring. If a newborn is sickly, or if its survival is not promising, they may cut their losses and favor the healthiest in the litter or try again later on.
In most cultures, neonaticide is a form of this triage. Until very recently in human evolutionary history, mothers nursed their children for two to four years before becoming fertile again. Many children died, especially in the perilous first year. Most women saw no more than two or three of their children survive to adulthood, and many did not see any survive. To become a grandmother, a woman had to make hard choices. In most societies documented by anthropologists, including those of hunter-gatherers (our best glimpse into our ancestors' way of life), a woman lets a newborn die when its prospects for survival to adulthood are poor. The forecast might be based on abnormal signs in the infant, or on bad circumstances for successful motherhood at the time -- she might be burdened with older children, beset by war or famine or without a husband or social support. Moreover, she might be young enough to try again.
We are all descendants of women who made the difficult decisions that allowed them to become grandmothers in that unforgiving world, and we inherited that brain circuitry that led to those decisions. Daly and Wilson have shown that the statistics on neonaticide in contemporary North America parallel those in the anthropological literature. The women who sacrifice their offspring tend to be young, poor, unmarried and socially isolated.
Natural selection cannot push the buttons of behavior directly; it affects our behavior by endowing us with emotions that coax us toward adaptive choices. New mothers have always faced a choice between a definite tragedy now and the possibility of an even greater tragedy months or years later, and that choice is not to be taken lightly. Even today, the typical rumination of a depressed new mother -- how will I cope with this burden? -- is a legitimate concern. The emotional response called bonding is also far more complex than the popular view, in which a woman is imprinted with a lifelong attachment to her baby if they interact in a critical period immediately following the baby's birth. A new mother will first coolly assess the infant and her current situation and only in the next few days begin to see it as a unique and wonderful individual. Her love will gradually deepen in ensuing years, in a trajectory that tracks the increasing biological value of a child (the chance that it will live to produce grandchildren) as the child proceeds through the mine field of early development.
Even when a mother in a hunter-gatherer society hardens her heart to sacrifice a newborn, her heart has not turned to stone. Anthropologists who interview these women (or their relatives, since the event is often too painful for the woman to discuss) discover that the women see the death as an unavoidable tragedy, grieve at the time and remember the child with pain all their lives. Even the supposedly callous Melissa Drexler agonized over a name for her dead son and wept at his funeral. (Initial reports that, after giving birth, she requested a Metallica song from the deejay and danced with her boyfriend turned out to be false.)
Many cultural practices are designed to distance people's emotions from a newborn until its survival seems probable. Full personhood is often not automatically granted at birth, as we see in our rituals of christening and the Jewish bris. And yet the recent neonaticides still seem puzzling. These are middle-class girls whose babies would have been kept far from starvation by the girls' parents or by any of thousands of eager adoptive couples. But our emotions, fashioned by the slow hand of natural selection, respond to the signals of the long-vanished tribal environment in which we spent 99 percent of our evolutionary history. Being young and single are two bad omens for successful motherhood, and the girl who conceals her pregnancy and procrastinates over its consequences will soon be disquieted by a third omen. She will give birth in circumstances that are particularly unpromising for a human mother: alone.
In hunter-gatherer societies, births are virtually always assisted because human anatomy makes birth (especially the first one) long, difficult and risky. Older women act as midwives, emotional supports and experienced appraisers who help decide whether the infant should live. Wenda Trevathan, an anthropologist and trained midwife, has studied pelvises of human fossils and concluded that childbirth has been physically tortuous, and therefore probably assisted, for millions of years. Maternal feelings may be adapted to a world in which a promising newborn is heralded with waves of cooing and clucking and congratulating. Those reassuring signals are absent from a secret birth in a motel room or a bathroom stall.
So what is the mental state of a teen-age mother who has kept her pregnancy secret? She is immature enough to have hoped that her pregnancy would go away by itself, her maternal feelings have been set at zero and she suddenly realizes she is in big trouble. Sometimes she continues to procrastinate. In September, 17-year-old Shanta Clark gave birth to a premature boy and kept him hidden in her bedroom closet, as if he were E.T., for 17 days. She fed him before and after she went to school until her mother discovered him. The weak cry of the preemie kept him from being discovered earlier. (In other cases, girls have panicked over the crying and, in stifling the cry, killed the baby.)
Most observers sense the desperation that drives a woman to neonaticide. Prosecutors sometimes don't prosecute; juries rarely convict; those found guilty almost never go to jail. Barbara Kirwin, a forensic psychologist, reports that in nearly 300 cases of women charged with neonaticide in the United States and Britain, no woman spent more than a night in jail. In Europe, the laws of several countries prescribed less-severe penalties for neonaticide than for adult homicides. The fascination with the Grossberg-Peterson case comes from the unusual threat of the death penalty. Even those in favor of capital punishment might shudder at the thought of two reportedly nice kids being strapped to gurneys and put to death.
But our compassion hinges on the child, not just on the mother. Killers of older children, no matter how desperate, evoke little mercy. Susan Smith, the South Carolina woman who sent her two sons, 14 months and 3 years old, to watery deaths, is in jail, unmourned, serving a life sentence. The leniency shown to neonaticidal mothers forces us to think the unthinkable and ask if we, like many societies and like the mothers themselves, are not completely sure whether a neonate is a full person.
It seems obvious that we need a clear boundary to confer personhood on a human being and grant it a right to life. Otherwise, we approach a slippery slope that ends in the disposal of inconvenient people or in grotesque deliberations on the value of individual lives. But the endless abortion debate shows how hard it is to locate the boundary. Anti-abortionists draw the line at conception, but that implies we should shed tears every time an invisible conceptus fails to implant in the uterus -- and, to carry the argument to its logical conclusion, that we should prosecute for murder anyone who uses an IUD. Those in favor of abortion draw the line at viability, but viability is a fuzzy gradient that depends on how great a risk of an impaired child the parents are willing to tolerate. The only thing both sides agree on is that the line must be drawn at some point before birth.
Neonaticide forces us to examine even that boundary. To a biologist, birth is as arbitrary a milestone as any other. Many mammals bear offspring that see and walk as soon as they hit the ground. But the incomplete 9-month-old human fetus must be evicted from the womb before its outsize head gets too big to fit through its mother's pelvis. The usual primate assembly process spills into the first years in the world. And that complicates our definition of personhood.
What makes a living being a person with a right not to be killed? Animal-rights extremists would seem to have the easiest argument to make: that all sentient beings have a right to life. But champions of that argument must conclude that delousing a child is akin to mass murder; the rest of us must look for an argument that draws a smaller circle. Perhaps only the members of our own species, Homo sapiens, have a right to life? But that is simply chauvinism; a person of one race could just as easily say that people of another race have no right to life.
No, the right to life must come, the moral philosophers say, from morally significant traits that we humans happen to possess. One such trait is having a unique sequence of experiences that defines us as individuals and connects us to other people. Other traits include an ability to reflect upon ourselves as a continuous locus of consciousness, to form and savor plans for the future, to dread death and to express the choice not to die. And there's the rub: our immature neonates don't possess these traits any more than mice do.
Several moral philosophers have concluded that neonates are not persons, and thus neonaticide should not be classified as murder. Michael Tooley has gone so far as to say that neonaticide ought to be permitted during an interval after birth. Most philosophers (to say nothing of nonphilosophers) recoil from that last step, but the very fact that there can be a debate about the personhood of neonates, but no debate about the personhood of older children, makes it clearer why we feel more sympathy for an Amy Grossberg than for a Susan Smith.
So how do you provide grounds for outlawing neonaticide? The facts don't make it easy. Some philosophers suggest that people intuitively see neonates as so similar to older babies that you couldn't allow neonaticide without coarsening the way people treat children and other people in general. Again, the facts say otherwise. Studies in both modern and hunter-gatherer societies have found that neonaticidal women don't kill anyone but their newborns, and when they give birth later under better conditions, they can be devoted, loving mothers.
The laws of biology were not kind to Amy Grossberg and Melissa Drexler, and they are not kind to us as we struggle to make moral sense of the teen-agers' actions. One predicament is that our moral system needs a crisp inauguration of personhood, but the assembly process for Homo sapiens is gradual, piecemeal and uncertain. Another problem is that the emotional circuitry of mothers has evolved to cope with this uncertain process, so the baby killers turn out to be not moral monsters but nice, normal (and sometimes religious) young women. These are dilemmas we will probably never resolve, and any policy will leave us with uncomfortable cases. We will most likely muddle through, keeping birth as a conspicuous legal boundary but showing mercy to the anguished girls who feel they had no choice but to run afoul of it.