“The little we know about love does not transcend simple observation, and the little we write about it has been written better by poets and novelists. But of greater concern is the fact that psychologists tend to give progressively less attention to a motive which pervades our entire lives. Psychologists, at least psychologists who write textbooks, not only show no interest in the origin and development of love or affection, but they seem to be unaware of its very existence.”
In a nutshell
Warm physical bonds in infancy are vital to our becoming healthy adults.
In a similar vein
Stanley Milgram Obedience to Authority (p 198)
Jean Piaget The Language and Thought of the Child (p 222)
Steven Pinker The Blank Slate (p 228)
B. F. Skinner Beyond Freedom and Dignity (p 266)
In 1958, primate researcher Harry Harlow was elected president of the American Psychological Association. In the same year he visited Washington DC, where the Association was having its annual meeting, to deliver a paper on his recent experiments with rhesus monkeys.
In the 1950s, American psychology was dominated by the behaviorists, whose endless experiments with lab rats aimed to show how easily the mammalian mind was shaped by its environment. Harlow and his wife Margaret went against the norm by studying monkeys, which they thought gave much better insights into human action. A straight talker, Harlow also refused to use terms like “proximity” when what he really meant was love. He told his audience:
“Love is a wondrous state, deep, tender, and rewarding. Because of its intimate and personal nature it is regarded by some as an improper topic for experimental research. But, whatever our personal feelings may be, our assigned mission as psychologists is to analyze all facets of human and animal behavior into their component variables. So far as love or affection is concerned, psychologists have failed in this mission.”
The behavioral doctrine was that human beings were motivated according to their primary drives of hunger, thirst, elimination, pain, and sex. Other motives, including love and affection, were secondary to these. In child rearing, affection was downplayed in favour of the belief in “training,” and there was little understanding of what we now know about the importance to babies of physical contact.
Harlow’s paper “The nature of love” turned all this on its head. With his refusal to see love and affection as simply a “secondary drive,” it became one of the most celebrated scientific papers ever written.
Harlow chose to work with young rhesus monkeys because they are more mature than human infants, and show little difference to human babies in how they nurse, cling, respond to affection, and even see and hear. The way they learn and even how they experience and express fear and frustration are also similar.
He noticed that, in the absence of contact with their mothers, these labraised monkeys became very attached to the cloth pads (actually diapers or nappies) that covered the hard floors of their cages. When they were periodically removed in order to put new pads down, the baby monkeys had terrible tantrums. This reaction, Harlow noted, was just like the attachment that human babies develop to a certain pillow, blanket, or cuddly toy. Startlingly, his research found that baby monkeys raised in wire-mesh cages with no pads had very little chance of surviving for more than five days. It seemed that “soft things to cling to” were not merely a matter of comfort, but in the absence of their mothers were a primary factor in the monkeys’ survival.
The behaviorist view was that babies—monkey or human—loved their mothers for the milk that they provided, since this satisfied a primary need. But what Harlow had seen with the cloth pads made him wonder whether babies might love their mothers not for their milk only, but because they provided warmth and affection. Perhaps love was as basic a need as food and water.
To test the idea further, Harlow and his team built a “surrogate mother” from wood covered with soft cloth, with a light bulb behind it providing warmth, and made another “mother” simply out of wire mesh. For four newborn monkeys, only the cloth mother provided milk and the wire mother did not; for four other newborns, the opposite was the case. The study showed that even when the wire mother was the one lactating, the monkeys vastly preferred to be with and have physical contact with the soft-cloth mother.
This result overturned the conventional wisdom that babies become conditioned to love their mother because she provides milk and is therefore their ticket to survival. Clearly, the ability to nurse was not the main factor for the monkeys; what mattered was the bodily contact, or the “mother’s love.” Harlow went so far as to suggest that perhaps the main function of nursing was to ensure frequent physical contact between baby and mother, since the loving bond seemed so vital for survival. After all, he noted, long after the actual sustenance stops, it is the bond that remains.
As real babies flee to and cling to their mothers at any sign of fear or danger, Harlow wondered whether this would still apply to baby monkeys even with a cloth or wire mother. It did, with the monkeys running to the cloth mother irrespective of how much this mother had “nursed” them. The same happened when the monkeys were placed in an unfamiliar room with new visual stimuli, and were given the opportunity to return to the cloth mother.
Harlow also found that monkeys that were separated from the surrogate mother for long periods (five months) still responded immediately to it if given the chance. The bond, once initially formed, was highly resistant to being forgotten. Even monkeys reared without any mother figure at all, real or surrogate, after a bewildered and frightened day or two in the presence of a cloth mother would warm to her and forge a relationship. After a while these monkeys expressed similar behavior to those who had enjoyed a surrogate mother all along.
In another variation, some of the surrogate mothers were given a rocking motion and also made to feel warm. Baby monkeys became even more attached to these mothers, clinging to them for up to 18 hours a day.
Was it the face of the surrogate mother, with her big painted-on eyes and mouth, that especially kindled the love of the baby monkeys? Harlow’s first surrogate-raised monkey only had a mother whose head was a ball of wood with no face, and she bonded with this surrogate over a period of six months. When later placed with two cloth mothers that had faces, the monkey actually turned the heads around so that she saw no face at all—just what she was used to in her mother! Again, Harlow’s experiment showed that what matters most is the close connection we form with our mothers, irrespective of what they look like and even how indifferently they treat us. Harlow was not joking when he wrote, “Love is blind.” He concluded that there was little difference in the quality of mothering provided by a surrogate or a real mother—it was apparent that the baby monkey needed only a very basic “mother figure” to grow up healthy and happy.
This assessment, however, turned out to be premature. Harlow observed that when his baby monkeys grew up, they had many things wrong with them. Instead of the normal range of responses, they swung between clinging attachment and destructive aggression, often tearing at their body or shredding bits of cloth or paper. Even as adults they had to cling to soft, furry things, and did not seem to know the difference between living and inanimate objects. Though they could be affectionate to other monkeys, few were able to mate as adults, and those who did have offspring were not able to take care of them properly. Clearly, the lack of normal response from their fake mothers, and their isolation from other monkeys, had made them socially backward. They had no idea what was or wasn’t appropriate behavior, no concept of the usual give and take of normal relationships.
What the Harlows discovered had actually been observed in the 1940s by Hungarian psychiatrist Rene Spitz. His well-known study compared babies raised in two institutional settings. The first was a foundling home that was very clean and orderly, but a little clinical; the second was a prison nursery, a rough-and-tumble sort of place where the children had lots of physical contact. Within a two-year period, over a third of the kids in the foundling home had died, whereas five years later all the prison nursery children were alive. Of the foundling home babies who did not die, many grew up with problems, with over 20 remaining institutionalized. What made all the difference was that the nursery kids’ mothers were allowed to care for them, while the foundling home’s children lived under a controlled regime run by professional nurses. Whether you define “death” as physical or psychological, it was the lack of physical affection and love that was the cause.
Critics say that all Harlow did was prove scientifically what was common sense—that babies and young children need to form a close physical and emotional attachment to someone as much as they need oxygen. But the task of proving beyond any doubt what we already know seems to be the role of experimental psychology, and it took Harlow’s experiments to change the way children’s homes and social service agencies were run. What began as defiance of the prevailing view on child rearing has now become conventional wisdom. For instance, the suggestion often given to new mothers that they should hold their minutes-old newborn against their bare skin can be traced back to the devastating effects of not having such contact, discovered by Harlow.
His work with monkeys also elevated what we now believe about the intelligence and capacity for feeling in animals. B. F. Skinner (see p 266) believed that animals had no feelings, but Harlow’s monkeys were creatures who thrived on curiosity and learning, and they had deep emotional needs.
Yet all this knowledge came at a price, for the great irony of the scientist who helped determine the “nature of love” was that his labs were often brutal places for the monkeys themselves. As he grew older, Harlow’s experiments got more cruel, and with good reason he became a focus of the animal liberation movement. Many of those who helped in these later experiments found the experience devastating.
For a more personal account of Harlow—his divorce, the death of his second wife, remarriage, issues with alcohol, and the quality of his parenting—read Deborah Blum’s Love at Goon Park: Harry Harlow and the Science of Affection (2003). The title comes from a nickname given to Harlow’s lab at the University of Wisconsin, whose address was 600 N. Park, which could easily be read as “Goon Park.” Many thought the name fitting, as with his antifeminist views, famous bluntness, and ruthless reputation as an experimenter, Harlow cut a frightening figure.
Born Harry Israel in Fairfield, Iowa in 1905, Harlow was an ambitious child whose intelligence gained him a place at Stanford University. He gained a BA and PhD, and when he was 25 was appointed to a position at the University of Wisconsin. About this time he changed his surname from Israel because, although he was Episcopalian, he was told that anti-Semitism would affect his career. Harlow soon established a primate psychology lab, and worked with IQ researcher Lewis Terman, and also Abraham Maslow.
Harlow stayed at the University of Wisconsin for most of his career, and was George Cary Comstock Research Professor of Psychology until 1974. He did a stint heading the Human Resources Research Branch with the US Army and lectured at Cornell and Northwestern universities among others. In 1972 he received a gold medal from the American Psychological Association, and in 1974 moved to Tucson to become an honorary professor at the University of Arizona.
His first wife Clara Mears worked with him on primate research, but they divorced in 1946. Harlow then married Margaret Kuenne (Marlow), and the year after her death in 1970, remarried Clara Mears. They had three sons and a daughter. Harlow died in 1981.