The academic quality of the nation's young teachers is taking a nosedive as a shortage of jobs causes capable students to shun courses in education and look elsewhere, according to a study published by a national education magazine.

To try to keep programs intact, college education departments have lowered their standards, the study suggests, providing a refuge for poor quality students who can't do well in more rigorous fields.

The study, by W. Timothy Weaver, an associate professor of education at Boston University, is based primarily on scores for nationwide tests, such as the College Board and Graduate Record examinations. Though these scores generally declined during the 1970s, the falloff was much steeper for education majors, Weaver reported.

Researchers for the National Education Association, the country's largest teacher group, questioned the significance of the test score decline.

"Einstein would probably have been at the top of all those tests," said Frank W. Kovacs, the NEA's research director, "but I'm not sure he'd be the best person to teach in the classroom . . . Some of the best teachers I've seen out there were not necessarily the brightest and the most competent in their subject, but they knew how to get it across to their kids and how to organize their classes so the bright kids could get it themselves."

Among signs of the "education brain-drain," Weaver listed these:

Average scores on the verbal part of the Scholastic Aptitude Test have dropped from 418 to 392 since 1973 among high school seniors intending to major in education. The average verbal SAT score for all college-bound seniors was 427 last spring, down 18 points from six years earlier.

The drop in mathematics SAT scores among students intending to major in education has been even greater -- down 29 points from 1973 to 1979, compared to a 14-point drop among all students. Last spring the average math SAT score for seniors intending to major in education was 420, which was 47 points below the average score for all students taking the test. Education ranked 27th among 29 fields for which scores were reported. The only ones with lower averages were ethnic studies and vocational training.

On Graduate Record Examinations, taken mostly by college seniors wishing to enter graduate schools, the scores of education majors "were substantially lower than scores of majors in eight other professional fields compared in 1975-76," Weaver reported. On the verbal part of the test, teacher majors were 25 points below average in 1976, compared to 7 points below average in 1970.

On the quantitative (mathematics) part of the test, teacher majors fell from 39 points below average to 51 points below average during the same span.

In the American College Testing program, whose exams are given mostly to college-bound students in the Midwest, elementary education majors dropped from the top one-third in English in 1970 to the bottom third in 1975. In math they fell from the top third to the bottom 5 percent.

On the other hand, Weaver reported that scores went up for students majoring in chemistry, engineering and agriculture -- all fields where jobs for college graduates have increased.

"When fields of study decline," Weaver said, "the first people to leave them are those with the highest test scores because they have the most options. Those who can't move out are left behind."

Weaver's study appeared in the September issue of the magazine published by Phi Delta Kappa, a 74-year-old national honor society of educators.

As school enrollments have slipped because of a nationwide decline in births, the number of new college graduates hired as teachers has dropped from 184,000 in 1970 to just 75,000 last year, according to NEA estimates.

The number of students graduating with bachelor's degrees in education also has fallen, though much less steeply -- from a peak of 195,600 in 1973 to 138,000 in 1978.

Weaver said a study financed by the U.S. Office of Education indicated that education graduates who took nonteaching jobs generally had higher test scores than those who went into teaching.

The decline in education majors would have been greater, Weaver said, if college departments hadn't lowered standards in order to survive.

This view is rejected by Edward C. Pomeroy, executive director of the American Association of Colleges of Teacher Education.

"If they are just filling up their seats with anyone who could walk," Pomeroy remarked, "then they aren't succeeding too well."

But Ralph Cyr, the association's research director, said he agreed with Weaver's data and conclusions.

"There's no doubt that schools of education in some cases had no choice but to lower their standards to maintain their enrollments," Cyr said. "It's hard to think about improving, you know, when you're up to your rear end in alligators."

Although there are no specific data to prove it, both Cyr and Weaver suggested that the decline in academic quality among women and blacks going into teaching may have been sharper than that for white men because the easing of discrimination has drawn bright women and jacks away from teaching and into higher-paying and more prestigious fields.

Women comprise about 70 percent of American teachers; blacks about 10 percent.

Despite the recent decline, teaching remains the second-largest occupation in the United States, with about 3 million persons, according to the U.S. Bureau of Labor Statistics. (Secretaries, who number about 3.4 million, are the largest occupation among the bureau's 150 categories.)

By contrast, the United States has just over 400,000 physicians and about 460,000 lawyers.

Being a mass occupation, teaching could never be as intellectually selective as medicine or law, Weaver said. In several studies in the 1950s and '60s, teachers placed about average in intellectual ability among all occupational groups and near the bottom for college graduates.

They are falling even lower now, Weaver said, which may account for widespread interest in competency tests for new teachers.

But Weaver said he thinks the tests themselves will lead to little improvement because the pool of teacher college graduates is generally of such low quality.

The only way to raise it over the long run, Weaver said, is to increase the opportunities for teachers, particularly in "nonschool" areas such as training adults for government and industry.