To the surprise of many psychologists, tests on infants as young as six months of age are predicting their scores on intelligence tests years later, when they start school.

While researchers continue to study and expand on the infant tests, doctors and clinical psychologists at 30 or more hospitals and clinics around the country are already using the tests to identify babies who are at special risk of doing poorly in school. Psychologists hope that they can give these children extra help to enhance their academic skills before they reach school age.

And now the developer of the first of these tests, Dr. Joseph Fagan, a psychologist at Case Western Reserve University, has taken the idea of infant testing a step further. Dr. Fagan recently reported that he can also identify babies likely to be above average in intelligence. One use of this finding, he said, might be to test babies from poor families to identify those who are particularly intelligent and could benefit from special enrichment programs, giving them the sort of advantages that children of upper-income parents are more likely to have.

Although in the best possible world, all children should have these advantages, Dr. Fagan said, in reality there are limited resources. Asked whether it was fair to give special attention to children who were predicted to be especially intelligent, Dr. Fagan replied, ”How about letting them waste away for five or six years? We have gifted children who don’t reach their potential because socioeconomic conditions just swamp them.”

Dr. Fagan’s suggestion that smart as well as less intelligent children could be identified is making some of his colleagues uncomfortable, in part because it pushes basic psychological research into the realm of social policy, and also because it raises serious questions about a movement to predict intelligence.

The very idea of predicting intelligence is already somewhat controversial. While intelligence tests administered to schoolchildren have proved accurate in predicting academic performance, many psychologists stress that there is more to intelligence than success in school.

Moreover, several studies have shown that tests that try to predict intelligence can have a self-fulfilling effect; the simple expectation that a child will do well or poorly will lead parents and teachers to treat the child in ways that may make the prediction come true.

”We are going too far in trying to predict intelligence early in life,” said Ina Uzgiris, a psychologist at Clark University in Worcester, Mass. ”A number of us would say that I.Q. is a hodgepodge of approximations that seem to correlate with schoolwork, but there certainly is more to doing well in life than doing well in school.”

”Intelligence is a funny word,” said Norman Krasnegor, who is chief of the human learning and behavior branch of the National Institute of Child Health and Human Development. ”There are many many ways to think of intelligence other than a score on a test.”

In a newly completed study, Dr. Fagan and his colleagues report that they can now test babies in the first year of life and pick out those who are likely to be above average in intelligence at age 3. Previous studies by Dr. Fagan and others had focused on identifying babies who are likely to do poorly in school. Dr. Fagan, who has formed a company to sell his test, has marketed it as a tool to study children at risk of being below average in intelligence, but he has not advertised it as a test to find those that may be above average in intelligence.

The infant intelligence tests have intrigued psychologists because they are the first baby tests that have any predictive value. Dr. Fagan and other independent researchers established their effectiveness in recently completed long-term studies in which babies were followed until they reached school age.

The tests, which attempt to measure what babies remember, are based on the assumption that they will be more interested in stimuli they have not previously encountered. One test involves showing infants photographs or pictures and measuring how long they look at them. In theory, babies will look at a new stimulus for a longer time than one they remember having seen before. Babies that are likely to be below average in intelligence will remember fewer of the stimuli they have seen before. Tests of Visual Memory

Variations involve testing whether babies remember sounds or objects they have felt but not seen.

Until the new tests were developed, researchers had tried to use infants’ motor skills as a measure of intelligence, but this method had ”zero predictability,” said Marc H. Bornstein, who directs family and child research at the National Institute of Child Health and Human Development in Bethesda, Md.

Working independently, Dr. Bornstein and Susan Rose of Albert Einstein College of Medicine in New York have found that a baby’s performance at age 4 months and 6 months on tests of visual memory correlate with I.Q. at 4 and 6 years of age. They used tests that they developed themselves but that are similar to those developed by Dr. Fagan. The predictions are independent of the parents’ education and income group, which also are correlated with I.Q.

But the predictions are by no means absolute, Dr. Bornstein said, and there is wide agreement that intelligence is determined both by genetics and by environment, which is one reason why children of more affluent and educated parents tend to score higher on I.Q. tests.

With the new tests, ”the only time we know for sure in our predictions is when a baby is way toward the low end of the scale,” Dr. Bornstein said. ‘Leg to Stand On’

Dr. Rose said she is particularly intrigued by the infant tests because they indicate that visual memory, which is already linked to I.Q. in later years, may be fundamentally tied to the workings of the mind. Visual memory may be a central aspect of intelligence from infancy onward. ”These new tests give us a leg to stand on in our feeling that we really are measuring something that is cognitive in nature,” Dr. Rose said.

Many researchers endorse the use of these tests to predict which babies may need special help to improve their chances of academic success. ”The early results of using Joe Fagan’s test are very promising,” said Craig T. Ramey, a psychologist at the University of North Carolina. ”His techniques are being used all around the country, by private pediatricians and in pediatric clinics and they are increasingly being discussed by people who are responsible for implementing education laws to help the handicapped.”

Dr. Krasnegor said: ”The law says that states can, if they wish, test children up to age 3 to see who has a learning disability and most states have mandatory testing of children between the ages of 3 and 6. We would like to find kids early on who are likely to have deficits that could lead to learning disabilities.”

At the same time, researchers are asking whether extra attention early in life will help children do better in school. Dr. Ramey and his colleagues conducted a national study of 100 children who are thought to be at risk of doing poorly in school because they were born prematurely and had low birth weights, both of which are correlated with an increased likelihood of learning disabilities. The researchers provided some of these children with special enrichment programs and designated others as controls who received no special help. Now Dr. Ramey and his colleagues are analyzing the data to see whether the enrichment programs helped the children perform better on preschool tests at age 3.

Dr. Ramey said he and others have previously found that enrichment programs can help children who are poor and culturally disadvantaged to do better in school. ”The findings imply to us that the early years are very important if you want to break the cycle of underaccompishment,’ Dr. Ramey said. Study of 55 Babies

Dr. Fagan’s recent study that he said distinguished between babies of average and above-average intelligence involved 55 normal, full-term babies born to upper middle-income families. ”They weren’t at risk for anything, except being smart,” Dr. Fagan said. He said the test of visual memory predicted that 28 of the babies would be above average in intelligence. After following the children for three years, he found that 21 of the 28 were above average in intelligence, measured with a standard test, the Peabody Picture Vocabulary Test-Revised. Seven of the 27 children who were identified as average when they were tested as babies had above-average intelligence when they were tested at age 3.

This raises the possibility of giving special help to these above-average children, starting early in life, Dr. Fagan said. ”I would like to see kids from disadvantaged situations identified early,” he said. ”Why not test infants and find out which of them could take more in terms of stimulation? It’s not going to hurt anybody, that’s for sure.” Other researchers are not so sure. ”We do need to do more for people of underprivileged backgrounds,” Dr. Uzgiris said. But, she added, if Dr. Fagan’s proposal were acted on, the babies who were not picked out as above average might be stigmatized. ”It would in some way cast a negative light on the others. They would be considered average, not as good. I think that sort of labeling would be detrimental. We would be writing some people off rather than trying to create an opportunity that would make the most of everybody.”

Dr. Bornstein said: ”Clearly, we’re all in favor of helping and doing as much as we can. But pegging a child is a different issue.”