The Science of Mother's Day

Some sad orphans
Some surprising rats
Those orphans again
Day care blues
Mice and men


The late Harry Harlow, a professor of psychology at the University of Wisconsin, with an infant monkey and wire surrogate mother.

Photo courtesy of the UW-Madison Archives.


Not really a monkey...
When she studied the effects of severe maternal deprivation under pioneering psychologist Harry Harlow, neuroscientist Mary Carlson probably never expected to see similar deprivation in human children -- especially thousands of them.

an infant monkey and wire model surrogate mother
Harlow's name is bonded to experiments that might be questionable today. For example, he separated a baby monkey from its mother and raised it in a cage with two substitute "mothers." The wire "mother" had a bottle for the infant, the cloth one didn't. Tellingly, as soon as the infants finished nursing, they abandoned the wire monkey and clutched the cloth one.

Even though the experiment demonstrated the primacy of nurture to sustenance, the cloth mother was not an adequate replacement: the isolated monkeys grew up with severe emotional and behavioral problems, says Carlson, associate professor of neuroscience and psychology at Harvard Medical School.

Even when raised in cages where they could see, smell and hear -- but not touch -- other monkeys, the infants developed what she called an "autistic-like" syndrome, with grooming, self-clasping, social withdrawal and rocking.

The theme of Harlow's work, she says, is that "You were not really a monkey unless you were raised in an interactive monkey environment."

Carlson says Harlow's demonstration of the power of social deprivation "directed my career." After a long period mapping nerve connections between the hand and the brain, she now studies the impact of abuse and isolation on the HPA (hypothalamic-pituitary-adrenal) axis, and on the powerful stress hormone, cortisol, made by the HPA.

mom! We've already described how touch modifies this important stress system in rats. Children show similar effects: a child vaccinated while sitting on a mother's lap has a relatively low rise in cortisol. (By the way, cortisol is usually measured in saliva. Drooling -- actually swabs of the mouth -- provides plenty of samples, so there's no need to jab kids for blood samples.)

In the orphanage
If Harlow's monkey experiments might be considered cruel today, what can we say about the human deprivation "experiment" in Romanian orphanages? Carlson says she found the whole affair "pretty shocking. We thought the whole world knew that institutional care was insufficient to maintain the social capacity of the human baby."

But not in Romania, where the long-time communist dictator, Nicolae Ceausescu, was a zealous believer in technological progress. Highly skeptical of all things touchy-feelie, he clamped down on psychology and social work in preference to engineering and science. He favored policies to raise the birth rate and established institutions for orphans and children whose parents could not care for them.

After Ceausescu was executed in the coup in 1989, the orphanages were opened to a world that saw Dickensian warehouses for the unwanted. Scientific study confirmed what the untrained eye could see: The children were in the third to tenth percentile for physical growth, and "grossly delayed" in motor and mental development, Carlson says. They rocked and grasped themselves like Harlow's monkeys, and grew up with weird social values and behavior.

As they aged, many of the orphans became homeless, with what Carlson calls "clumsy, sad, all inappropriate" social interactions. To express affection, one boy might kiss another -- on the top of the head. Smiling and ingratiating, the youths are superficially friendly but unable to form permanent attachments. Like characters in a gloomy sci-fi novel, many found work in the secret police, where their lack of loyalty and ability to make "friends" were saleable traits.

Chemical analysis showed abnormal cortisol profiles, indicating a severe problem with the stress response. Carlson compared children living under improved conditions to the rest of the orphans -- and found their cortisol looking more normal. Another indication that the stress response can respond to conditions came from a study by Carlson of Romanian children in poor-quality day care. During the week, cortisol was abnormal, but when they returned home for the weekend, it looked more normal.

To Carlson, the issue is not simply science, but human rights. Romania, like every other country except the United States and Somalia, has ratified the United Nations Convention on the Rights of the Child, obligating it to provide foster or adoptive parents to orphans, rather than cold institutions.

The goal of her research, she says, is not simply to prove that neglect causes hormonal changes, but also to prevent future abuse. "We felt Romania was in violation of the rights of the child, and we thought maybe a molecule [cortisol] would make a strong argument -- to people who did not find the behavior" compelling enough.

Indeed, things have begun looking up in Romania: the new president has established a Children's Office and declared the intention to close the orphanages. Workers in the orphanage she studied have started cuddling the children and trying to teach colleagues about children's emotional needs.

Closer to home
As the day-care results indicate, strong stress reactions can occur after mistreatment that's less severe than total deprivation. Says Michael Meaney of McGill University, who studies stress reactions in rats, "You don't need to go into abuse, extreme neglect to see these effects. Even in the normal range of behavior, [abuse] can result in extraordinary differences in the HPA stress response."

Changes in the stress response early in life could explain how identical twins can wind up with different personalities, Meaney says. "The development of individual differences is determined largely by an individual's environment early in life." Yet he stresses that the stress response is not always bad. "It's a beautifully integrated response that helps meet the demands of stressful situations."

It's just that preparing for stress becomes counter-productive if life proves less stressful than the animal "anticipated."

To Carlson, the Romanian research has another implication. The consistent relationship between poor care and abnormal cortisol raises the question of what's happening to American children in poor day care.

To many working parents, the idea of finding -- and using -- day care is stress enough.

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