Mothers and Others

by Sarah Blaffer Hrdy

  The recognition that a child’s survival depended not just on staying in contact with his mother or provisioning by his father but also on the availability, competence, and intentions of other caregivers in addition to parents is ushering in a new way of thinking about family life among our ancestors. Well might anthropologists and politicians remind us that “it takes a village” to rear children today. What they often leave out, however, is that so far as the particular apes that evolved into Homo sapiens are concerned, it always has. Without alloparents, there never would have been a human species.

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  NOVEL DEVELOPMENTS

  The truth is that the least-studied phase of human development remains the phase during which a child is acquiring all that makes him most distinctively human.

  —John Bowlby (1969)

  “There is no such thing as a baby,” the child psychiatrist David Winnicott liked to say. “There is a baby and someone.” The someone he had in mind was the mother. Winnicott’s was an apt summation from the early years of attachment theory, and it remains an apt maxim so far as other apes are concerned. But recent research in infant psychology indicates that little humans are casting their nets more broadly to encompass others as well as mothers, evaluating their intentions and learning from their actions. In the original Bowlbian equation, infant survival in our “environment of evolutionary adaptedness” depended on the baby’s relationship with his mother, which is true as far as it goes. But that equation is incomplete when applied to babies born in societies like those of our Pleistocene ancestors. Maternal commitment, and ultimately child survival, entailed a baby plus mother plus others.

  No one advocating this expanded equation would dispute that a mother is unusually responsive to her baby and that maternal signals of commitment have a special salience for infants.1 By two months of age a baby’s relationship with his mother is likely to include long, seemingly soul-seeking mutual looks. By the end of two months, increasingly alert babies look even longer, while their eyes squint, their pudgy cheeks bob upward, and the corners of their mouths rise into deliciously appealing social smiles that invite the mother to keep right on loving. But others are being invited to join in as well. By the time the baby is three months old, his smiles and gestures begin to be accentuated by attractive coos and chortles, and by seven months full-fledged babbling is heard.2 All the while the baby is acutely sensitive to how responsive his mother is, but he is taking note of others as well.

  Mothers have no precise equivalent in the way they respond to their babies. But in communities where people live in close quarters, the mutual gazes and rhythmic, playful looks engage others as well as mothers (think of how readily a human infant engages in a game like peek-a-boo). Psychologists refer to the high-pitched patter that adults use when addressing babies as “motherese.” However, in contexts where females other than the mother also interact with babies, alloparents as well lapse into high-pitched, melodic tones on the order of “Oooh, are you all right?” (Skeptical? Try talking to a baby, any baby, for a length of time and see what happens to your voice.) Since chimpanzee, orangutan, and other ape infants are rarely out of touch with mothers, they have far less need for this infantile equivalent of sex appeal. Nor do their mothers have the same need for reassuring banter.

  In foraging societies, then, just who converses with babies or talks in motherese? Among people like the Aka, where either the mother or a familiar alloparent is in constant tactile contact with a baby, Hewlett reports that mothers spend little if any time talking to their babies in this cooing way.3 Among the !Kung, alloparents and mothers are about equally likely to offer the infant some object to examine, and equally likely to encourage him or utter some prohibition. But overall, lumping together various interactions with sibs, cousins, fathers, and other adults, nearby caregivers are more likely to speak to babies in motherese and entertain them than their mothers are.4 These “others” start vocalizing to infants from their first days of life, and keep right on doing it.5

  Cultures vary tremendously in the significance accorded to babbling, in what people say to babies (and how they say it), and in the rituals they perform. Babies may be swaddled or wear diapers. They may be draped with amulets, dusted with talcum, basted with palm oil, or ceremoniously finger-painted with protective symbols. But regardless of language or custom, the message conveyed by such ministrations is equivalent: You are cared for and will continue to be. Love (and that is a perfectly good word for what we are talking about here) is a message babies are all too eager to receive, and small wonder. How secure an infant feels depends on how responsive the mother is to his physical and emotional needs. Where resources are scarce, there is likely to be a positive correlation between maternal commitment, a child’s feeling of attachment to his mother, and the child’s nutritional status, since committed mothers pay more attention to keeping their babies fed.6 But mothers are not the only ones who care.

  Even as information from traditional societies with a great deal of alloparental involvement flowed in, such cases continued to be viewed as atypical. Bowlbian stereotypes of continuously available, chimpanzeelike mothers prevailed. Textbooks emphasized continuous-care-and-contact mothering among the !Kung and implied that this was both typical of “the” hunter-gatherer and also optimal for natural human development. By the beginning of the twenty-first century, even as systematic data came in from African societies with high levels of shared care, anthropologists continued to consider shared care as unusual and to refer to societies with high levels of alloparental care as having a “unique childrearing system.”7 The paradigm shift away from thinking of our Pleistocene ancestors as reared by all-nurturing chimpanzeelike mothers, and toward thinking of them as apes with species-typical shared care, has been slow in coming. Only in the past decade have cooperative breeding’s implications for attachment theory begun to be addressed, and its evolutionary implications taken into account.8

  In this chapter, I describe findings by a small group of often selfconsciously iconoclastic developmental psychologists who, long before me, began to consider how infants might form multiple attachments—a first step toward expanding and refining mother-centered models for human evolution. Next I consider how their findings relate to what comparative primatologists and child developmentalists have learned about the probable impact on a helpless ape of growing up dependent on multiple caretakers rather than a single caretaker. What are the psychological implications for an infant when his mother’s initial response to him, as well as her availability over time, is contingent not just on her own past experience and physical condition but also on her perceptions about who else is around and willing to help? How does contingent maternal commitment affect an infant’s need and desire to understand and engage others? How does dependence on (and even becoming emotionally attached to) multiple others affect an individual’s outlook during his lifetime, as well as over the many lifetimes that cumulatively add up to evolutionary change?

  THE EXTRA SOMETHING HUMAN BABIES LOOK FOR

  As attachment theorists have long assumed, all primate infants evolved to seek contact with a warm and nurturing mother. There is no questioning Bowlby’s insight on this point. But unless she was incapacitated, a chimpanzee, orangutan, or gorilla mother’s motivation to maintain tactile contact with her baby was nearly as strong as her baby’s powerful urge to stay attached to her. Such babies had little occasion to worry about psychological ambivalence on the part of their mothers. Nor did they need to fret about separation from mothers with whom they were in constant contact anyway. Any chimpanzee or orangutan under six months of age who found himself off his mother was very likely an orphan already, a little ape with awful prospects.

  At some point in the emergence of the genus Homo, however, mothers became more trusting, handing even quite young infants over to others to temporarily hold and carry. A little ape might be separated from his mother for variable amounts of time. A baby thus had far more incentive to monitor his mother’s wherea
bouts and to maintain visual and vocal contact with her, as well as far more motivation to pay attention to her state of mind and also to the willingness of others who might be available to care for him when his mother was disinclined. I propose that such separations, together with the chronic challenges and uncertainties they posed, caused little apes, already endowed with considerable gifts for reading (and even imitating) the facial expressions of others and with the neural equipment for rudimentary mind reading, to devote even more time and attention to interpreting the intentions of others, an activity which in turn would affect the organization of their neural systems.9

  All primates are born innately predisposed to seek tactile contact with somebody or, in the worst-case scenario (think of Harry Harlow’s terrycloth-covered wire “surrogate” mothers), to something. But human infants seem to require more than the warm, soft, tactile stimulation that monkeys so obviously seek.10 Yes, human babies become attached to inanimate objects like security blankets or teddy bears, but primarily as backups when more animated and communicative sources of security are out of reach.11 By the second or third month, human babies actively seek a higher level of emotional responsiveness, mediated by increasingly long and expressive looks and by high-pitched, soothing queries.12 When the psychiatrist Ed Tronick asked mothers to don expressionless “still-face” masks, babies who failed to find the emotional responses they sought became apprehensive. When the artificial face looking back at them continued to appear blank, they became distressed.13

  From about eight months onward, babies become increasingly interested in other people’s reactions—the beginnings of what you might call intellectual curiosity. Really, though, it’s a more elemental concern having to do with how much value another person ascribes to some object the baby is holding or, perhaps even more importantly, to the baby himself, as in “What does this other person think and feel about me and what I am doing?” Babies don’t just register what other people find nice or frightening and allow that to shape their own response, as in the “social contagion” and “social referencing” seen in many primates and other animals as well. Rather, human babies seek to understand what others think or feel about the object they are looking at or handling; they scan the faces of mothers and alloparents not just to predict what they will do (other animals do that) but to gauge their impressions of what they see, to use these caregivers as “curators of meaning.”14 I remember games with my own children much like those described for the !Kung. Infants who up to that time have held objects in an iron-clad grasp will “show” the object to others and then miraculously release it so as to give the object to someone else. For weeks this game, repeated again and again, is a source of interest, excitement, and profound satisfaction.

  By six months of age, babies are storing away information about which other individuals are likely to be helpful, as recently demonstrated by Yale University psychologists Kiley Hamlin, Karen Wynn, and Paul Bloom. Six- and ten-month-old infants were given a puppet show in which anthropomorphic shapes either helped or hindered an unknown third party who was trying to climb a steep hill. When the infants subsequently had an opportunity to choose which cartoonlike character they wanted to play with, infants showed a robust preference for the helpful characters. Long before infants have words to describe a concept like helpfulness, they readily discriminate between someone likely to be nice and someone potentially mean, and they act on this knowledge when eliciting assistance.15 By the time humans really start attending to the intentions, reliability, and effectiveness of others, they are combining this information with assessments of their potential benevolence.

  Psychologists like Michael Tomasello refer to “the nine months revolution”—the time when babies’ “understanding of other persons as intentional agents like the self” begins to more fully develop.16 In light of how much alloparental food sharing goes on in traditional societies, it is worth noting that by this age even infants who are still far from being weaned are spending much more time with alloparents and are on the receiving end of kiss-fed treats. One of Bowlby’s initial early insights had to do with recognizing that an infant’s attachment to his mother is separate from his quest for milk (the “cupboard” theory of love).17 But this does not mean that interest in and preferences for various caretakers (mother included) are not going to be influenced and conditioned by food rewards. Delectable gifts are factored into a child’s perception of who is generous and who is not, right along with assessments about who wants to help and who might hurt.

  No doubt having a larger and more complex neocortex than any monkey does, along with attendant cognitive and linguistic gifts, is going to factor into children’s sophisticated social assessments and preferences for particular caregivers.18 But their curiosity about other people’s reactions and their quite nuanced evaluations of “character” are traits that have been sharpened by a long evolutionary history of coping with complex early environments and with contingencies that are far less predictable than those with which other baby apes had to cope.19 As early as their first year of life—far earlier than, until recently, most psychologists would have thought possible—human babies exhibit concern with what someone else not only thinks but thinks about them. For example, babies obviously bask in what can only be described as personal pride when they sense they are approved of, and they act shamed or embarrassed when they sense that something they have done is not okay with their caregivers.20

  If human babies are sensitive to such signals, it follows that they are capable of attributing mental and emotional states to others—that is, they are capable of some level of intersubjective involvement. I am arguing that the most plausible way to explain this difference between humans and other apes is to take into account the vast stretch of time (perhaps as long as two million years) during which babies who were better at gauging the intentions of others and engaging them were also better at eliciting care, and hence more likely to survive into adulthood and reproduce. Children who develop this way are also going to be naturally more responsive to disapproval, social sanctions, and behaviors affecting not just status but reputation.

  CONNOISSEURS OF COMMITMENT

  All primates are born with a suite of traits that help them stay in touch with their mothers.21 Taken off his mother, a baby will flail and complain, though under some conditions he readily becomes accustomed to being held by someone else (his father, in the case of a titi monkey). Even among infant-sharing species, babies initially resist leaving their mother and are typically relieved to be returned. When they are not returned, their calls become more and more plaintive—to my maternal ears, unbearably so. After his initial protest at separation, the baby’s symptoms of distress escalate as he looks around for his mother and calls loudly so as to bring her back. Young langur monkeys have a specialized, high-pitched, birdlike trill precisely adapted to the rare mishap of prolonged separation. The call really does sound like a bird, presumably so that passing predators will register the caller as a winged creature liable to fly off rather than as helpless prey.

  The less accustomed babies are to being consoled by others, the stronger their distress. If not consoled, the baby’s desperate searching for its mother will be followed by obvious signs of misery. Eventually, the baby sinks into an energy-saving torpor characterized by all the earmarks of despair.22 Such evident, palpable suffering is why the most thoughtful pioneers from back in the Harlow era—scientists like Robert Hinde at Cambridge University—have concluded that given what we now know, it is no more ethical to experimentally separate baby monkeys from their mothers than to engage in other forms of animal torture.23

  Once reunited with his mother, an infant subjected to prolonged separation and attendant despair may respond with what Bowlby termed “detachment,” a self-reliant-seeming superficial bravado that presumably would help a luckless infant cope in spite of having an unreliable mother. Self-reliance might even lay the groundwork for forging new, if necessarily less discriminating and less profound, attachment
s to such substitute caregivers as might present themselves.24 Indiscriminate attachments by youngsters who approach and make overtures to available adult candidates in an effort to adopt a mother-surrogate are typical of children and monkeys alike.25 The similarities will be obvious to anyone who has watched heart-breaking videos from research experiments where infant monkeys are separated from their mothers, or has visited orphanages or refugee camps where—because of poverty, war, AIDS, or indifference—children who find themselves with neither parents nor alloparents desperately seek substitutes. Recognizable too will be our own deeply rooted responses to their distress, along with the near-overwhelming impulse to scoop these children up and offer succor. After all, we are primates as well.

  Human infants’ biologically based drive to seek out and maintain attachments builds on a highly conserved set of behaviors found among all primates.26 Decades ago, Bowlby’s colleague, Mary Ainsworth, pointed out that “there is nothing implicit in attachment theory that suggests that sensitive maternal responsiveness is required for infant attachment formation.”27 Yet human babies still seem to need something more than tactile contact, some extra reassurance of maternal commitment. Throughout the evolutionary history of other apes, the mother was either there and highly motivated to remain in continuous touch with her baby or else she was incapacitated and probably dead. By contrast, the challenges confronted by early human infants have always been more complicated.

  Such a legacy helps explain why, even in the first months before a baby’s brain is anything like fully developed, months before he is capable of learning a language, a human infant is sensitive to how responsive his caretakers are with a connoisseurship that goes beyond the universal primate need for a secure base. A human baby gravitates toward enlivened eyes, a lively tone, the cadences of a voice that seems to echo his own, ever attentive to the give-and-take and mutual pacing of responses as if he was using the lilt in a mother’s murmurings as well as her overall attunement to his own internal state—all the rhythms implicit in the interactions between these two beings—as indicators of commitment. It should come as no surprise then that newborns whose mothers are depressed and less responsive to infant cues exhibit neurological and physiological profiles indicative of stress (as measured by high levels of serotonin and dopamine). Compared with other babies, their brain waves are characterized by more activation in the right frontal lobe (as traced by electroencephalograms), and they are less easily soothed by listening to music (as gauged by delayed heart-rate deceleration).28