Nice Girls Do: Steven Pinkers Evolutionary “Explanation” of Infanticide


Robert L. Morrison

Article ID:



Jun 20, 2023


Apr 20, 2009

This article first appeared in the Christian Research Journal, volume 20, number 4 (1998). For further information or to support the Christian Research Journal please click here.



MIT psychology professor Steven Pinker recently wrote a New York Times Magazine article in which he claimed that legal prohibitions against infanticide were difficult to defend. He reached his provocative conclusion using the methods and assumptions of a currently stylish academic discipline broadly known as “evolutionary psychology.” A close examination of his argument shows it to be sensationalist, arbitrary, self-contradictory, misleading, and poorly informed by ethical theory and moral reflection. Sadly, there were few public rebuttals to Pinker’s article, suggesting that our society’s widespread callousness toward fetal life may also be broadening to include neonatal life as well.


One of the hippest intellectuals around recently argued in polite company that it’s difficult to defend laws against killing a baby. But he hardly drew a yawn.

Steven Pinker, an MIT psychology professor and best-selling author, presented his argument in a 2 November 1997 New York Times Magazine article entitled Why They Kill Their Newborns. The article attempted to shed light on the “prom mom” phenomenon of recent headlines. Pinker maintains that giving birth and then discarding the newborn in the trash is (of all things) best explained as an indirect result of species-preserving evolutionary adaptations. On this basis, Pinker eventually concludes, “The baby killers turn out to be not moral monsters but nice, normal (and sometimes religious) young women.”

Surprisingly (or not?), Pinker’s article evoked little response. According to Boston Globe columnist John Ellis (who stridently attacks Pinker), the published response to the article was virtually nonexistent. “Only Michael Kelly, former editor of the New Republic and now a weekly columnist for the Washington Post, raised his voice in protest.” Both responses from Ellis and Kelly were sharply critical of Pinker and raised some important points.1 Yet Pinker claimed in his rebuttal letters to the editors of the Post and the Globe that Ellis and Kelly had distorted his argument. Furthermore, all three failed to raise some important questions. Consequently, there is much to learn from a closer look at Pinker’s argument, the responses it evoked, and his rebuttals.

For what it’s worth, some girls who kill their babies no doubt are religious, at least in some utterly conventional sense of the term. “Nice” and “normal,” however, are tougher to apply. If all Pinker means is that many of these girls appear to be nice and normal before killing their babies, then he may be right. The question of whether they should be considered nice and normal after or in light of committing infanticide is, of course, much more difficult. True to form, Pinker does not take the trouble to clarify.

Pinker uses the term “neonaticide” instead of “infanticide.” This is ostensibly to introduce a distinction between the killing of a newborn and the killing of an older baby or child (“filicide”), such as South Carolina resident Susan Smith’s drowning of her two young children a few years ago. This, however, seems like a euphemism. After all, no one ever referred to the Susan Smith incident as “infanticide” simply because the children involved were not infants. Indeed, Pinker himself uses the term “infanticide” in his briskly selling book How the Mind Works, from which some of the article’s material is drawn, and in general his writing shows little tolerance for euphemisms. So perhaps the editors at the New York Times Magazine suggested something a little more obscure and delicate.


Pinker cites studies from Europe and the U.S. to show that observers, laws, juries, and judges are usually more lenient toward mothers who kill newborns than toward mothers like Susan Smith. Pinker, however, does not merely encourage leniency; rather he feels forced to question the personhood of infants: “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.” But Pinker seems willing to fudge his estimate of American attitudes to show whatever he pleases. In this article, he speaks of our leniency and understanding. Yet in How the Mind Works, Pinker claims that Americans view the killing of newborns as “a synonym for depravity.”2 The apparent reason for this double-talk is that in this article he’s questioning the personhood of infants and laws against infanticide, while in his book he’s clarifying Darwinian assumptions and hinting that a better understanding of them might alleviate Americans’ love affair with infants.

Pinker quickly discards some explanations for infant killing that he considers inadequate: “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.” Pinker apparently has in mind not just recorded history, but prehistoric times as well. Yet he offers no substantial evidence for his detailed claim about ancient, unrecorded attitudes. Certainly, even in more modern societies infanticide occurs with disturbing frequency. Pinker surely cannot be faulted for noting its frequency. Much more surprising is his claim that infant killing is accepted in most cultures throughout history. Pinker seems to make the dubious assumption that the leniency often shown to teen mothers who kill their newborns counts as cultural “acceptance” of the practice. Using this logic, we might urge that our culture “accepts” teen gang violence as well.

In any event, Pinker appears to take a reassuring moral tack by urging that “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.” Surely this is a refreshing claim in contrast to common attempts to reduce all troubling human behavior to pathology. Unfortunately, however, the possibility of forgiving those who commit infanticide while still opposing and punishing their crimes appears to escape Pinker.

John Ellis charged Pinker with claiming that “baby-killing was not indefensible.” In his rebuttal3 Pinker reminds Boston Globe readers of his disclaimer: he did write, “Killing a baby is an immoral act.” Pinker then asks rhetorically, “Can one be any clearer than that?” — to which the obvious answer is yes — much clearer. Merely noting for the record that something is an immoral act tells us nothing about its moral severity. Since Pinker suggests that killing a newborn should not be considered as serious as murder, we may guess that he considers it serious, but perhaps not heinous. If he were as clear as possible, however, we wouldn’t have to guess. The real problem, though, is that although Pinker here says neonaticide is immoral, he later clearly implies that an understanding of human life that morally permits it is the only viable one. In addition, he states that legal proscriptions against infanticide are scarcely defensible. Add to this Pinker’s unclear claim that those who kill their babies turn out to be “nice and normal,” and we have a mixed and dangerous message. One would certainly hope that Pinker would not discuss rape or domestic violence, for example, in similar terms. Would doing so be clear, let alone morally responsible? So why is Pinker so coy about infanticide?

There is a shocking casualness to Pinker’s tone. A similar ease of expression has served him well in his superbly written books How the Mind Works and The Language Instinct, where he has cultivated an engaging “academic bad boy” style. Yet in a discussion that deals in large part with the morality of infanticide, his tone suggests a disturbing callousness. Pinker appears scarcely more concerned in his discussion of infanticide than we might imagine him to be if he were discussing tire disposal. That’s the real problem with the article.


In his effort to explain the biological roots of infanticide, Pinker attempts to construct a model of maternal choice that involves the rationing of resources so as to help a species survive. In support of this he cites biological evidence and anthropological and psychological studies indicating that

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 healthier 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….

Pinker then (implausibly) depicts new mothers as initially detached and unencumbered by emotional ties to their children, while they decide whether or not to let them live: “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.”

Having stipulated this model of maternal choice, Pinker then attempts to forge a link between the model and teenagers who have recently committed neonaticide, such as Amy Grossberg (who together with Brian Peterson fractured their newborn’s skull and left the child’s body in a dumpster) and Melissa Drexler (who gave birth to a child at her high school prom and left the child dead in the bathroom trash): “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.” In other words, Pinker believes the mothers are victims of a powerful adaptive strategy that has been encoded into their genes through natural selection. This genetic influence in turn exerts a powerful emotional pressure when women give birth in dire circumstances as, for example, in a motel or a rest room.

Pinker continues, “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.” “Most observers sense the desperation that drives a woman to neonaticide,” he continues, and then puts forth what for him is the bottom line: “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-ager’s actions….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.” If Pinker is right, we might add that the laws of biology (not to mention the teen parents themselves) were certainly unkind to the infants involved as well. It’s rather telling that Pinker expresses concern over the unkindness of biological laws even to his latte-sipping readers while failing to mention the cruelty suffered by infants who are killed by one or both parents. Perhaps Pinker is rationing his mammalian sympathy resources.

Here we face a serious problem in Pinker’s argument: What is the connection between the coolly assessing mothers of Pinker’s general model of evolutionary triage and the “immature,” “panicked,” “desperate,” and “anguished” victims of biology that emerge from his description of current teenage mothers who kill their infants? It is not clear that Pinker fully recognizes the disparity here, and he doesn’t give his readers much on which to go.

He does make much of the understandable duress involved in bearing a child alone or in secret, and notes that “in hunter-gatherer societies, births are virtually always assisted, because human anatomy makes birth (especially the first one) long, difficult and risky.” But, of course, hunter-gatherer societies aren’t the least bit unique in this respect; births are virtually always assisted and difficult in every society. Pinker also appears to forget that Grossberg was accompanied by the baby’s father, while Drexler gave birth in the bathroom at her high school prom. Thus it isn’t entirely clear how the isolation factor applies to Grossberg or Drexler, though it obviously might apply to other girls who give birth in secret. Yet even considered by themselves, Pinker’s descriptions of women in hunter-gatherer societies and of teen mothers in our society remain puzzling.

In Pinker’s general description of maternal choices, we find a perplexity. He tells us that “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” (emphasis added). Here, however, the evidence apparently contradicts Pinker’s claim that mothers don’t form an emotional attachment toward their infants until the days after their cool assessment and decision. Where is there any emotional tie in Pinker’s model of coolly assessing mothers that could possibly account for such lifelong anguish over having killed the infant?

In his description of teen mothers in our society, Pinker seems correct (at least, in some cases) in noting that the woman is “immature enough to have hoped that her pregnancy would go away by itself.” But when this is the case, how plausible is it to hold that the girl is psychologically normal, as Pinker maintains? Surely such extreme denial can hardly be chalked up to ordinary immaturity. Meanwhile, Pinker provides us no alternative explanation of this phenomenon.

It’s difficult to know what to make of the argument here, since Pinker has left so many loose ends. His theory appears to require cool maternal calculation to explain why a mother would possibly discard an infant, but it also appears to require an anguished, desperate state of mind to explain why we should consider mothers who discard infants to be nice, normal young women who are victimized by the laws of biology. It is difficult to grasp in much detail how Pinker’s explanation could possibly work, other than that ancient evolutionary imperatives have created an emotional mechanism that will sometimes push, but not coerce, young women to kill their infants. Yet, if the “explanation” doesn’t make sense, then it doesn’t even amount to wild speculation — hardly the kind of thing anyone should use as a basis for questioning an infant’s personhood.


Even more serious difficulties arise when Pinker turns to an ethical discussion of infanticide. Again, he assures us he’s no relativist: “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.” Pinker then notes that the only thing both sides in the abortion debate agree on is that the boundary must be drawn before birth. He dismisses conception as such a clear boundary, devoting merely a sentence to it. Pinker devotes another sentence to dismissing the pro-choice argument for viability as a boundary, noting that viability is a “fuzzy gradient.” His assumption is that “the endless abortion debate shows how hard it is to locate the boundary.” But here he appears to confuse “locate the boundary” with “reach consensus on the boundary” and to assume that failure to reach a consensus provides a legitimate excuse for scarcely trying to locate a defensible prebirth boundary. Yet surely the “endless debates” over political, economic, or psychological issues don’t deter Pinker from attempting to discover the truth or embracing and defending opinions in these areas. Pinker’s hasty dismissals seem disingenuous.

In light of the difficulty Pinker sees in drawing a line beyond which a right to life can be assumed, one might hope he would urge a restraining respect for life on the basis of moral prudence, if nothing else. It’s far better to draw the human circle too wide than too narrow. But that would be a vain hope: Pinker doesn’t even consider this possibility. Instead, Pinker presses on: “Neonaticide forces us to examine even this boundary [birth]. To a biologist, birth is as arbitrary a milestone as any other.”

One might naturally feel outraged that Pinker would question even birth as a shining bright moral line in a discussion of infanticide. Indeed, this is where Kelly and Ellis express their disgust; but what Kelly and Ellis fail to note here is that Pinker (and the biologists) are urging precisely a point that all pro-life proponents have in common and that few pro-choice proponents even question: Of course there is nothing either biologically or morally magical about birth that somehow bestows a right to life. Here Pinker is just being biologically clear-headed. He hardly tells us anything new or interesting; we don’t need a biologist to tell us how arbitrary it is to confer a right to life on a baby simply because it is outside rather than inside the womb. What is not so banal is that Pinker has now painted himself into a moral corner.

By now we can see how Pinker implies that the only place a moral line can defensibly be drawn is after birth. The demonstration is rather straightforward. Pinker has quickly dismissed the possibility of drawing a line before birth, and he has likewise quickly and rightly dismissed the possibility of drawing a line at birth. What else remains?

In his rebuttal to Ellis, Pinker asserts, “That does not mean that we can do without a boundary, and I most certainly did not write that the boundary should come after birth.” Again, Pinker is only technically correct; he did not write that. But he has clearly implied it by ruling out two of the three logically exhaustive possibilities. As we might expect, given this implication, Pinker continues with an evaluation of the notion that the line might be drawn after birth. Here he is not dismissive.

Since clear-headed biology alone can’t settle the question, Pinker cites philosophers: “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.”

Here Pinker uses the word debate in a somewhat misleading manner. Surely the mere fact that a few people may discuss or entertain the idea that newborns are not persons or that infanticide ought to be permitted during an interval after birth does not mean that there exists any true moral dilemma. Indeed, the few moral philosophers who entertain such notions are, among ethicists, the equivalent of “flat-earthers.” Unfortunately, though, the absence of a true moral dilemma is fully compatible with the presence of a true moral crisis, such as profound and widespread moral callousness toward fetal and neonatal life.

While suggesting that he has the solid backing of significant numbers of moral philosophers, Pinker forges on in pursuit of a clear line of demarcation after which a right to life exists: “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.”

Yet again Pinker seems right in his biology but wrong in his ethics. Surely a newborn, like a field mouse, lacks any of the qualities Pinker lists. So what? If the unnamed moral philosophers Pinker cites approvingly were correct in claiming that these traits are necessary conditions of a right to life, then Pinker has proven way too much: killing an infant becomes no more serious than killing a mouse. Further, why should we restrict our compassionate understanding to mothers who kill their newborns? Why not extend it to fathers or indeed anyone who kills a newborn — say a surly bystander who doesn’t like the sound of crying — since in this view the infant possesses no more personhood than a mouse? And if a newborn does not possess a right to life, then how could anyone maintain that an animal — which by all accounts will never attain the personal qualities specified by Pinker’s moral philosophers — might ever deserve our protection? Even more disturbing, what protection will there be for those born with mental disabilities that partially or wholly prevent them from developing the traits proposed by Pinker’s unnamed moral philosophers? Pinker does not consider these and many other troubling questions raised by his position. What most people (both philosophers and nonphilosophers alike) would consider a reduction to absurdity, Pinker apparently considers a bold, dispassionate argument.

Sadly, Pinker seems unaware of some basic distinctions used by most ethicists. For example, following his moral philosophers Pinker claims that the right to life must be based on certain peculiarly human moral traits. Yet, as noted above, he does not address the myriad difficulties this perspective raises. In so doing, he overlooks a vital distinction that others have raised in the abortion controversy. Gilbert Meilaender, himself a moral philosopher, describes this distinction quite well and correctly notes its far-reaching importance:

At stake here is the development and enlargement of our concept of human community. Perhaps the ability to sustain a bond of affection that unites us across generations is as fundamental as “self awareness” for our understanding of what it means to be human. Moreover, there are deeper theoretical difficulties with a narrow and exclusivistic understanding of personhood. For there is a difference between the characteristics that distinguish the human species, and the qualifications for membership in the species. It may be that among the distinguishing characteristics of humans are features such as rationality and self-consciousness. But one can be human without exercising (or even having the capacity to exercise) such characteristics. To be human one need only be begotten of human parents. Indeed, those who lack some of these capacities are best described as the weakest and least advantaged members of our community.4

Surely Pinker fails to recognize the vital importance of this distinction between the qualifications for membership in the human community and the characteristics that distinguish the human species. Pinker also does not seem to recognize that the narrow definition of personhood given by his unnamed moral philosophers completely undermines his expressed intention of avoiding a slippery slope that leads to the disposal of inconvenient people and grotesque deliberations about the value of individual lives. Consequently, Pinker is himself engaged in such a discussion scarcely half a page later.


In leaving a rich and massive tradition of nuanced moral reflection and argument untapped, while resorting to single-sentence dismissals and caricatures, Pinker displays shocking irresponsibility for a scholar, especially one who is addressing such a serious matter. Pinker himself criticizes such an approach to moral discussion in How the Mind Works: “The debate over human nature has been muddied by an intellectual laziness, and unwillingness to make moral arguments when moral issues come up.”5 Exactly! So why, when it comes to something as serious as infanticide, doesn’t Pinker practice what he preaches?

There are many truly lamentable things about Pinker’s argument and its apparent failure to arouse significant protest within the American cultural mainstream. Instead of increasing his readers’ understanding, he offers explanations that are in some respects more baffling than the issues they seek to explain. Instead of stimulating readers’ moral sensibilities, he anesthetizes them by summarily dismissing the logical alternatives to infanticide and then fatuously bemoaning the difficulty of providing grounds for outlawing infanticide. Consequently, what ought to be axiomatic — that an infant has a right to life — becomes at best difficult for Pinker to defend. Surely none of this is the least bit necessary to try to understand some of the reasons behind infanticide or even to argue that some lenience should be shown to teens who commit it. Instead, Pinker’s concluding ethical argument proves to be an offensive, sensationalist exercise.

Pinker unwittingly reminds those of his readers who need such reminders just how slippery the slope is between abortion and infanticide. In this connection, Kelly confesses that Pinker’s article shocked him out of his naïve assumption that our society would not eventually debate even more terrible constrictions of the human circle.

Pinker also deserves thanks for his clear-headed, nonsentimental reminders — in this article and elsewhere — of historical evil. He admits that the reminders are banalities, but they are made necessary by the blindness of intellectual fashion. In How The Mind Works, Pinker reminds readers that nature and humans are not necessarily nice: “Like many species, Homo sapiens is a nasty business. Recorded history from the Bible to the present is a story of murder, rape, and war, and honest ethnography shows that foraging peoples, like the rest of us, are more savage than noble.”6 Perhaps, then, Pinker has confronted us with a terrifying question concerning human nature: Are those who kill their infants all too nice and normal?

Robert L. Morrison has a Ph.D. in religion from Boston University. He lives in Arlington, Massachusetts.



  1. John Ellis, “It’s Ok to Kill Babies? And That’s Fit to Print?” Boston Globe, 29 November 1997, A15; Michael Kelly, “Arguing for Infanticide,” Washington Post, 6 November 1997, A23.
  2. Steven Pinker, How the Mind Works (New York: W. W. Norton and Company, 1997), 443.
  3. “Letters to the Editor,” Boston Globe, 3 December 1997.
  4. Gilbert C. Meilaender, Body, Soul, and Bioethics (Notre Dame: University of Notre Dame Press, 1995), 110.
  5. Pinker, 47.
  6. Ibid., 50–51.
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