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Model of efficiency: ¡®hospitalism¡¯ produced infants who were listless, apathetic and refused to eat ¨C the result not of disease but of loneliness

¡±Their children¡¯s cries unheard, that past through fire

To his grim idol.¡±

John Milton, Paradise Lost (1667)

The infants had been arranged into neat rows, swaddled in aseptic white cloth the way precision instruments would be secured for shipping. Masked, hooded and gloved nurses cautiously moved down the aisle to record vital functions and administer bottles of formula, closely adhering to the feeding schedule detailed in their log books. To eliminate the possibility of contamination, any handling of their charges was kept to a minimum and parental visits were strictly forbidden. It was a model of efficiency compromised only by the piercing screams of newborns in distress.

American infant wards in the first half of the 20th century were designed around two prevailing ideas, wrote Robert Sapolsky, a Stanford University neuroscientist, in his book Monkeyluv: And Other Essays on Our Lives as Animals (2005): ¡°a worship of sterile, aseptic conditions at all costs, and the belief among the (overwhelmingly male) paediatric establishment that touching, holding, and nurturing infants was sentimental maternal foolishness¡±. But there was little doubt at the time that eliminating cross-infection was a medically necessary pursuit.

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Well into the 1920s, according to statistics from Bellevue Hospital in New York, an estimated 30 per cent of infants died before they could go home with their mothers. Many more experienced a condition referred to as ¡°hospitalism¡±, in which extended stays produced infants who were listless, apathetic and refused to eat. It wasn¡¯t until 1941 that New York paediatrician Harry Bakwin, in a paper read before the American Pediatric Society, told a sceptical audience of his peers that they had been deceiving themselves all along: hospitalism was not the result of disease, he said. It was caused by ¡°loneliness¡±.

There are few American cities that feel more like an incubator than Houston, Texas in the summertime. With its thick, stagnant air and searing heat, often reaching highs of 40degC in July, the city¡¯s torrid atmosphere drapes over the coastal plain like the heavy fabric of an influenza tent. During the city¡¯s post-war economic boom, fuelled by abundant petroleum reserves and an expanding military-industrial complex to supply, Houston experienced rapid exponential growth. Row upon row of identical white housing developments emerged almost overnight, spreading the metropolis outwards in all directions like bacteria filling an agar plate.

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Sarah Blaffer Hrdy was born on 11 July 1946 and grew up in an environment that epitomised an American exceptionalism that would define the second half of the 20th century - but only if you were male and white.

¡°This was a very segregated and really quite patriarchal society,¡± Hrdy tells me from her home at Citrona Farms near the University of California, Davis, where she held a chair in anthropology until her retirement. ¡°Growing up in Houston was a lot like growing up in South Africa.¡±

When she later moved to Cambridge, Massachusetts, first to attend Radcliffe College and then graduate school at Harvard University, Hrdy embarked on a distinguished 40-year career as a primatologist and evolutionary theorist who would come to challenge - and ultimately transcend - an interpretation of Darwinian biology still moored in Victorian attitudes about gender and the role of mothers in natural history. But it would be Hrdy¡¯s early years in southeast Texas and her unconventional career path as she tried to balance work and family that would ultimately inspire her ideas and motivate her to persevere.

As the third daughter born into a wealthy family - Hrdy¡¯s paternal grandfather, Robert L. Blaffer, was a founder of the Humble Oil Company, which later merged with Standard Oil of New Jersey to become Exxon - her surroundings were permeated by distinctly ¡°Southern¡± genteel values, especially where women¡¯s roles were concerned. But she was also subject to the prevailing attitudes in child psychology of the time, which regarded overt expressions of love and affection as a parental weakness that could spoil a child¡¯s character.

¡°Educated women in my mother¡¯s generation¡±, explains Hrdy, ¡°thought that if you responded to a crying baby you would be conditioning that baby to cry more and to be more demanding. Of course, today we know the opposite to be the case.¡±

The most prominent advocate for this spartan approach towards parenting was another member of the Southern gentry, John B. Watson, the South Carolina-born psychologist and president of the American Psychological Association. Founder of the ¡°behaviourist¡± school in psychology, Watson saw himself as engaged in nothing less than an all-out war against the evils of maternal love. His 1928 bestseller, Psychological Care of Infant and Child, sold 50,000 copies in its first year and remained one of the most widely read parenting manuals for decades to come.

Watson¡¯s advice called for a draconian and emotionally restricted approach to childrearing. ¡°Never hug and kiss them,¡± he wrote, ¡°never let them sit on your lap. If you must, kiss them once on the forehead when they say good night. Shake hands with them in the morning.¡±

The child¡¯s mind, Watson believed, was a tabula rasa, a blank slate, and their behaviour had to be moulded to fit the demands of society. The individual consequences of failure could be dire.

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¡°Mother love is a dangerous instrument which may inflict a never-healing wound,¡± he insisted, ¡°an instrument which may wreck your adult son or daughter¡¯s vocational future and their chances for marital happiness.¡±

For a Southern lady of Hrdy¡¯s status, the most important concern was that one should marry well to establish a position in society, and her parents were determined to spare their children the emotional attachments that might threaten those opportunities. Employing a succession of governesses to raise her children, Hrdy¡¯s mother regularly found a replacement whenever the children became too attached.

¡°No one ever doubted that my mother loved her five children,¡± Hrdy says, but as a result of her upbringing, ¡°I was a case study in insecure attachment and, except with friends, quite shy.¡± Hrdy would eventually learn to overcome her shyness, but the absence of an emotional bond during her early development left behind a permanent scar: to this day she has no memory of childhood.

In 1990, after Hrdy¡¯s brother died tragically at the age of 30, she received his baby book from their early childhood in Houston.

¡°I was amazed by how much detailed information there was in it,¡± she says. Having only vague impressions of their distant caregivers, Hrdy couldn¡¯t imagine that one of them had kept such a complete record.

¡°But then I looked more closely and I realised that it was my handwriting,¡± she says. ¡°I was keeping all of these detailed notes on my brother¡¯s development, but I have no recollection of caring for him.¡±

The precise mechanism for such childhood memory loss continues to be debated by psychologists, but the common experiences of adults who share this kind of amnesia form a consistent pattern. Like those children who suffered the effects of hospitalism in the early part of the 20th century, the absence of childhood attachment with a caregiver results in physiological changes that have potentially lifelong consequences.

¡°I want to know so much more about my early childhood and I simply don¡¯t,¡± Hrdy confesses. ¡°I have a feeling that others of my generation and social class are very much in the same boat.¡±

But during the past few years her research into the evolutionary biology of childhood attachment has convinced her that the problem lies much deeper than her own generation¡¯s experience.

Hrdy believes that flawed assumptions about what children need to feel secure permeate our society, influencing decisions by parents and policymakers alike. ¡°I think we have an epidemic of emotional neglect of children today that has gone completely unrecognised.¡± If she¡¯s right, what can be done to reclaim a childhood lost?

Hrdy is not the first evolutionary theorist to experience childhood memory loss. When Charles Darwin was eight years old, his mother died after a protracted illness. In keeping with proper Victorian sensibilities, no one in the Darwin family was permitted to acknowledge the emotions they experienced as a result of her loss. While trying to reconstruct this experience in his autobiography many years later, Darwin wrote of his mother: ¡°it is odd that I can remember hardly anything about her¡±.

He added: ¡°I believe my forgetfulness is partly due to my sisters, owing to their great grief, never being able to speak about her or to mention her name.¡±

Soon after his mother¡¯s death, young Charles was sent away to boarding school where he was regarded as kind but intensely shy with a tendency towards reclusiveness that would come to define his later years. Throughout his life he would suffer from a strange, psychosomatic illness that doctors were at a loss to explain.

The English psychiatrist John Bowlby, in his biography of the world¡¯s most famous naturalist, attributed Darwin¡¯s ailments to what today would be referred to as ¡°panic disorder¡± brought on by separation anxiety and an inability to properly mourn his mother¡¯s loss. In Darwin¡¯s own words, his adult years were plagued by persistent bouts of ¡°vomiting preceded by shivering, hysterical crying, dying sensations or half-faint (and) nervousness when E. (Emma, his wife) leaves me¡±. He experienced similar cases of abdominal distress and cardiac palpitations as a young man - long before his five-year voyage on HMS Beagle - suggesting that the source of his affliction wasn¡¯t something contracted during his foreign travels but rather had an origin closer to home.

For Bowlby, one of the first scientists to consider childhood from an evolutionary perspective, Darwin¡¯s mysterious illness and childhood memory loss provided one more piece of evidence suggesting that our species is adapted to make secure attachments with a caregiver as part of our biological inheritance. However, to convince psychologists steeped in behaviourism to accept such a radical proposal would require evidence from the primates that Darwin made it his life¡¯s work to bring us closer to.

At the same time that Bowlby was developing his evolutionary theory of attachment in the mid-1950s, a hard-drinking, chain-smoking workaholic by the name of Harry Harlow was busy creating separation anxiety in the lab. While his original intention was to discover the cheapest way to breed monkeys for experimentation, Harlow ended up providing empirical evidence to refute those psychologists who advocated a cold, emotionless approach to parenting by creating the kind of wiry caregiver that they described, quite literally.

By placing a baby monkey into a cage with two artificial ¡°surrogate¡± mothers - one made of soft terrycloth and the other a patchwork of wire mesh - Harlow sought to test the behaviourists¡¯ assumption that an infant was motivated only by a parent who provided them with nourishment. In the course of the experiment, eight identical cages would be established, but with one important variation: in four of them, only the ¡°wire mom¡± would be equipped with a bottle, while in the other half only the ¡°cloth mom¡± would be. If the behaviourists were correct, the infant should prefer whichever ¡°mother¡± was the source of food.

The results were unambiguous: in both cases infants spent nearly all of their time clinging to their cloth mother regardless of whether or not it was the one with the bottle. In the cages where wire mom was so equipped, the infants would leave soft mom¡¯s embrace to feed, only to immediately return for the ¡°contact comfort¡± they obviously required.

¡°The effects were so strong¡±, wrote Deborah Blum, the Pulitzer prizewinning journalist who chronicled Harlow¡¯s experiment in her book Love at Goon Park: Harry Harlow and the Science of Affection (2002), ¡°that the scientists began to wonder about other ways to test that bond and the security that seemed to come with it.¡±

Harlow next placed each infant - along with both surrogate mothers - into a 6 sq ft playspace that the monkeys could explore independently. When cloth mom was present, the infants would each hesitantly wander around their novel environment, confident that they could return to the safety of their surrogate¡¯s embrace if they needed to. But in those trials where Harlow had cloth mom removed, the infants would huddle in the corner screeching, sucking their hands or rocking back and forth repeatedly. Even those infants who were used to feeding from wire mom had a similar response: she was no better than the strange objects that surrounded her.

Subsequent experiments, this time with flesh-and-blood mothers, found that only those infants who had first established a secure attachment could successfully forge relationships with other members of their group. Without this, infants would experience heightened anxiety in social situations, just as Bowlby described for children with insecure attachment.

¡°Harlow¡¯s animal studies were meticulous because he knew how controversial they were going to be,¡± Blum tells me. ¡°When added to Bowlby¡¯s work [they] provided the bedrock foundation that started switching the behaviourist way of thinking in the opposite direction.¡±

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However, for all the importance that Bowlby and Harlow placed on childhood attachment, they felt this role was entirely the purview of the mother. ¡°This whole business of mothers going to work, it¡¯s so bitterly controversial, but I do not think it¡¯s a good idea,¡± Bowlby told an interviewer in 1989, reflecting views that dated back two decades. ¡°Children are looked after in indifferent daycare nurseries.¡±

Harlow was even more direct in an interview for Psychology Today in 1973: ¡°God created women to be mothers and essentially nothing else.¡±

As career-driven men in a patriarchal culture, Bowlby and Harlow found it unthinkable that men should take an active role in childrearing. ¡°They were products of their time,¡± Blum says. ¡°Science doesn¡¯t exist in a vacuum: it is influenced by the culture around it and can influence the culture in turn.¡±

As a young student walking to class beneath the granite gaze of revered university patriarchs, Hrdy found the same sexism permeating her environment, and there were no role models she could look to for support.

¡°The year I graduated from Radcliffe [1969], there was not a single female professor at Harvard,¡± Hrdy says, ¡°and as a graduate student in the 1970s, I was my professor¡¯s first [female] student.¡±

Attending seminars as a postdoctoral researcher, her infant daughter tucked into a sling so as to maintain the constant physical contact that Bowlby¡¯s attachment model of parenting recommended, Hrdy experienced first-hand the results of the prevailing sexism. Anthropology lectures would focus on the benefits of women being exchanged between groups as a way of connecting male brotherhoods and strengthening alliances. The savannah baboon social system, where males compete and form alliances with each other for access to females who had no role other than mothering, was held up as the model for our Pleistocene ancestors.

Nowhere did theories of human origins or models of behaviour consider the female perspective, or study what was adaptive for children. Male behaviour was viewed as the prime mover of evolution: women and children were merely satellites in its orbit.

¡°Primate behaviour, and the whole evolutionary endeavour, was steeped in these very Victorian preconceptions,¡± Hrdy said. ¡°I remember thinking to myself: ¡®This is what it must be like to be a black person listening to a lecture in support of the Ku Klux Klan.¡¯¡±

To make matters worse, colleagues who had been trained with this perspective would at times dismiss her work with distinctly sexist overtones. To cite just one example, when the prominent biologist Robert Trivers was asked to comment on Hrdy¡¯s groundbreaking work on primate infanticide in 1979, he told a reporter: ¡°My own view is that Sarah ought to devote more time and study and thought to raising a healthy daughter. That way misery won¡¯t keep travelling down the generations.¡±

For Hrdy, such comments only added to the burden of gender inequality that she had shouldered all her life.

As it turns out, there is a direct connection between male-biased societies and the attitudes expressed towards women. Research in cultural anthropology in the decades after Bowlby has shown that what anthropologists call ¡°patrilocal societies¡± - societies in which men stay in the communities they are born into while women marry into outlying regions - tend to be more patriarchal, with an emphasis on controlling women¡¯s freedom of movement, expression and reproduction. Societies with more flexible residence patterns, in which females have the option to remain in their home group near helpful kin or to move between groups, tend to be more egalitarian with higher levels of female control over their own lives and the lives of their children. Hunter-gatherers, the foraging societies that most closely approximate how our Pleistocene ancestors would have lived, are generally multi-local, with parents opportunistically moving between father¡¯s and mother¡¯s kin, or even joining some new group.

However, most farming societies today are based on patrilocal residence - and this suggests that a dramatic shift occurred when humans first invented agriculture approximately 12,000 years ago.

¡°Over time, as populations built up, as property became much more important - and it also became important to defend property - that¡¯s when boundaries became less porous and men stayed together,¡± Hrdy says. With patrilocality and the influence of patrilineal descent, there emerged a heightened concern over female chastity. Control over women became increasingly important, and reduced autonomy for mothers came at the expense of children. ¡°While patriarchal ideologies promote fertility,¡± Hrdy says, ¡°they undermine child well-being.¡±

The striking differences between the status of females across primate societies led Hrdy to develop her theory of cooperative breeding in human evolution.

¡°I realised that there was simply no way a species with young as dependent as human children are could have evolved unless parents had access to alloparents - individuals other than the genetic parents - who helped to care for and also provide for the youngsters,¡± she says. Human children may be 18 years old before they produce as many calories as they consume. The result of this high level of dependency can be seen among hunter-gatherer societies today.

¡°The characteristic feature of hunter-gatherers is the giving environment,¡± says Barry Hewlett, professor of cultural and evolutionary anthropology at Washington State University. After more than 20 years conducting fieldwork in the Central African Republic, what really stands out for him is just how many different members of the group provide parental care.

¡°It makes sense,¡± he argues. ¡°They¡¯re all genetically related to the child so many other individuals could be interested in providing care.¡±

More recent research on genomic imprinting suggests that our Pleistocene ancestors also involved networks of caregivers in the raising of children. In many species, the genetic relationship between kin members is a powerful predictor of how much investment one relative will provide in support of another. This may also be true of humans: paternal grandmothers have been shown to share more genes with their granddaughters than with grandsons.

A study published in the Proceedings of the Royal Society journal in 2010 tested the hypotheses that granddaughters would survive better when a paternal grandmother was present and grandsons would survive better when a maternal grandmother was present. The prediction was strongly supported in nearly all cases using data from societies ranging from 17th-century Japan and 18th-century England to present-day Gambia and Ethiopia.

¡°This evidence with grandmothers is increasingly impressive now and is absolutely consistent with a genomic-imprinting approach,¡± says Trivers, professor of anthropology and biological sciences at Rutgers, the State University of New Jersey. ¡°It must be an effect of grandmothers directly providing investment.¡±

Hrdy says that Trivers, who turned 69 last month, is the most inspirational teacher she ever had. His theoretical papers on reciprocal altruism, parental investment and parent-offspring conflict, all developed while he was a graduate student and later a teaching assistant at Harvard, were among the most important contributions to biology in the 20th century.

Trivers and Hrdy know each other well, but their relationship had to overcome a rocky start. It took a while before Hrdy realised just how much Trivers had to offer. His habit of speaking off-the-cuff strained relations between them, particularly in 1979 when he made his infamous comment to the press that said Hrdy should stick to being a mother.

Afterwards, he immediately regretted saying it. ¡°I swore the person to secrecy, and they promised, but that was the only quote they used,¡± he tells me. ¡°It hurt her and she was a personal friend.¡±

Years later, Trivers came to the defence of his former student when one of the leading evolutionary biologists of the time - his old Harvard adversary, the late Stephen Jay Gould - criticised Hrdy¡¯s idea that female orgasm was the product of natural selection, a view that is now widely accepted.

¡°It makes you wonder¡±, Trivers told a national newspaper, with obvious delight, ¡°just how close Steve had ever been to that blessed event if he thought it was a side-effect.¡±

The uniting of behavioural and genomic evidence, something that Hrdy and Trivers have independently explored throughout their careers, has revolutionised the way that mothers and children are viewed from the perspective of natural history. And rather than an evolutionary logic that places men at the top of the hierarchy, followed by women and children at lower levels, the perspective has now been inverted.

¡°Instead of the classical, so-called ¡®patriarchal¡¯ society,¡± Trivers says, ¡°the logic goes the other way around: children; women as primary investors; lastly and hardest to justify, males.¡±

In turn, what Hrdy finds is that a supportive network of caregivers is an evolutionarily stable strategy, ensuring children have many attachment figures. Patriarchal society isolated mothers by creating an environment that immured them from the social support that has long been the hallmark of our species. The image of the mother as ¡°an all-giving, totally dedicated creature who turns herself over to her children¡±, says Hrdy, is not one that ¡°takes into account the woman¡¯s perspective¡±.

In the stifling heat of another Houston summer, this time in 2001, a woman named Andrea Yates killed her five children by drowning them in a bathtub.

¡°What was that mother - already identified as suffering psychological duress - doing alone with five children without social or institutional support of any kind?¡± Hrdy asks me rhetorically. In the background, I can hear her youngest son, Niko - named after the Nobel prizewinning ethologist Nikolaas Tinbergen - arrive home. A network of other relatives are busily preparing for a family gathering. ¡°We have forgotten to put events like these murders into a larger perspective,¡± she adds.

Hrdy believes that for hundreds of thousands of years, mothers and children were given the physical and emotional support that allowed our species to thrive. Hunter-gatherers have always relied on a network of attachments so that, should one caregiver fail, many others could ensure emotionally confident and secure individuals.

¡°Rates of child mortality were high, but there was no child abuse or emotional neglect,¡± Hrdy told me. ¡°A child that experienced the kind of emotional neglect it takes to produce the psychopathology of insecure attachment, the kind showed in Bowlby¡¯s and Harlow¡¯s research, simply would not have survived.¡±

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An environment that contained a network of support for mothers and children was formative in our species¡¯ development. We have forgotten these memories today and, as a result, deceived ourselves about what children, and our society as a whole, ultimately need to feel secure.