Broadcast: September 2, 2003
This is Sarah Long.
And this is Bob Doughty with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we discuss recent findings about how intelligence develops in babies.
Not long ago, many people believed that babies only wanted food and to be kept warm and dry. Some people thought babies were not able to learn things until they were five or six months old.
Yet doctors in the United States say babies begin learning on their first day of life. The National Institute of Child Health and Development is an American government agency. Its goal is to discover which experiences can influence healthy development in humans.
Research scientists at the institute note that babies are strongly influenced by their environment. They say a baby will smile if her mother does something the baby likes. A baby learns to get the best care possible by smiling to please her mother or other caregiver. This is how babies learn to connect and communicate with other humans.
The American researchers say this ability to learn exists in a baby even before birth. They say newborn babies can recognize and understand sounds they heard while they were still developing inside their mothers.
One study shows that babies can learn before they are born. The researchers placed a tape recorder on the stomach of a pregnant woman. Then, they played a recording of a short story.
On the day the baby was born, the researchers tested to find out if he knew the sounds of the story repeated while inside his mother. They did this by placing a device in the mouth of the newborn baby.
The baby would hear the story if he moved his mouth one way. If the baby moved his mouth the other way, he would hear a different story. The researchers say the baby clearly liked the story he heard before he was born. They say the baby would move his mouth so he could hear the story again and again.
Researchers in Finland have shown that babies can learn while they are asleep. They demonstrated that newborn babies can learn to identify different spoken sounds while sleeping.
The Finnish researchers divided forty-five newborns into three groups. They used devices to measures the babies’ brain activity. The researchers played recordings of spoken sounds for up to one hour while the babies slept
After this brief period, the researchers continued to play the recording to one group of babies during the night. The second group heard a different recording. The third group did not hear any recording. The researchers studied each baby’s brain activity. Those in the first group could identify the sounds in the morning and again at night. The other babies could not.
The head of the study believes that babies can learn while asleep because the part of their brains called the cerebral cortex remains active at night. The cortex is very important for learning. This part of the brain is not active in adults while they sleep.
Many experts say the first years of a child’s life are important for all later development. An American study shows how mothers can strongly influence social development and language skills in their children.
The study involved more than one-thousand-two-hundred mothers and children. Researchers studied the children from the age of one month to three years. They observed the mothers playing with their children four times during this period.
The researchers attempted to measure the sensitivity of the mothers. The women were considered sensitive if they supported their children’s activities and did not interfere unnecessarily. They tested the children for thinking and language development when they were three years old. Also, the researchers observed the women for signs of the mental condition called depression.
The children of depressed women did not do as well on tests as the children of women who did not suffer from depression. The children of depressed women did poorly on tests of language skills and understanding what they hear.
These children also were less cooperative and had more problems dealing with other people. The researchers noted that the sensitivity of the mothers was important to the general health of their children. Children did better when their mothers were caring, even when the women suffered from depression.
Another study suggests that babies who are bigger at birth generally are more intelligent later in life. It found that the intelligence of a child at seven years of age is directly linked to his or her weight at birth. Study organizers say this is probably because heavier babies received more nutrition during important periods of brain development before they were born.
The study involved almost three-thousand-five-hundred children. Researchers in New York City used traditional tests to measure intelligence. Brothers and sisters were tested so that the effects of birth weight alone could be separated from the effects of diet or other considerations.
The researchers found that children with higher birth weights generally did better on the intelligence tests. Also, the link between birth weight and intelligence later in life was stronger for boys than for girls.
Another American study examined the development of very low birth weight babies. They were born early, before the end of the normal nine-month development period.
Researchers in Cleveland, Ohio studied two-hundred-forty-two people who were born in the late Nineteen-Seventies. At birth, they weighed an average of one-thousand-one-hundred-seventy-nine grams. On average, they were born during the twenty-ninth week of pregnancy. By comparison, a pregnancy is considered full term at thirty-seven weeks.
The researchers compared the progress of those born early with other children over a twenty-year period. They found that the young people who had been very low birth weight babies were less likely to complete high school. They also did not perform as well on intelligence tests as other adults.
However, the very low birth weight adults were less likely to use drugs or alcoholic drinks. They also were less likely to become pregnant before the age of twenty.
A long-term American study shows the importance of early education for poor children. The study is known as the Abecedarian Project. It involved more than one-hundred young children from poor families in North Carolina.
Half of the children attended an all-day program at a high-quality childcare center. The center offered educational, health and social programs. Children took part in games and activities to increase their thinking and language skills and social and emotional development.
The children attended the program from when they were a few weeks old until the age of five years. The other group of children did not attend the childcare center. After the age of five, both groups attended public school.
Researchers compared the two groups of children. When they were babies, both groups had similar results in tests for mental and physical skills. However, from the age of eighteen months, the children in the educational child care program did much better in tests.
The researchers tested the children again when they were twelve and fifteen years old. The tests found that the children who had been in the childcare center continued to have higher average test results. These children did much better on tests of reading and mathematics.
Recently, organizers of the Abecedarian Project completed another examination of the students who are now twenty-one years old. They were tested for thinking and educational ability, employment, parenting and social skills.
The researchers found that the young adults who had the early education still did better in reading and mathematics tests. They were more than two times as likely to be attending college or to have graduated from college.
The study is more evidence that learning during the first months and years of life is important for all later development.
This VOA Special English program, SCIENCE IN THE NEWS, was written by George Grow. It was produced by Cynthia Kirk. This is Bob Doughty.
And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.