The life sciences have been downgraded in the White House advice mills in recent months.

There used to be four assistant directors in the Office of Science and Technology Policy (OSTP), and one, Dennis Prager, handled the life sciences. But when Prager resigned earlier this year his job was abolished. He is being replaced by two medical researchers from the National Institutes of Health, but they will operate at a lower staff level, reporting to an assistant director rather than directly to Director George A. Keyworth II or his deputy.

Carl M. Leventhal is a program director with NIH's National Institute of Neurological and Communicative Disorders and Stroke. He is also a former deputy director of what was then the National Institute of Arthritis, Metabolism, and Digestive Diseases, and before that a deputy director of the Bureau of Drugs at the Food and Drug Administration.

Gordon D. Wallace is a senior investigator in the laboratory of viral diseases at the National Institute of Allergy and Infectious Diseases. He was formerly an administrator in the agency, and his background is in veterinary medicine, including work in tropical diseases of animals.

NIH sources consider both well-qualified scientists, rather than political choices. Bruce Abell, an OSTP spokesman, said the two "will make us very strong in the life sciences". But Roberta Miller of the Consortium of Social Science Associations said, "They may be very competent . . . but the problem is if they are to represent the life sciences, they may have a hard time representing the life sciences as a whole, because both come out of medicine."

In addition to medicine, the life sciences include biology, agriculture and the social and behavioral sciences. As for the social sciences, Abell said no one at the OSTP will be designated now to handle "a subject as narrow as that."

At the same time that the life sciences have been put on a lower rung than such subjects as space, energy and natural resources, the White House has put together a new advisory body, the White House Science Council, which is heavily loaded with physicists. Only one of the 13 council members is not a specialist in the physical sciences: Donald Frederickson, an M.D. and former NIH director.

The changes at the OSTP are in keeping with two themes repeatedly enunciated by Keyworth: priorities must be established among the sciences and science must bolster industry and the national defense. Physics is not only Keyworth's field, but, along with engineering and related sciences, is most closely linked to national defense and rejuvenating American industry.

In his briefing on the fiscal 1984 budget this year, Keyworth said that the life sciences are important, but have been doing very well in recent years and so need relatively less help now.

But the idea sounds less reasonable to researchers. Herschel Liebowitz, a psychologist at Pennsylvania State University, complained that the 1984 Reagan budget for the National Science Foundation is "an attempt to establish a hierarchy among the sciences" with social sciences on the lowest rung.

The NSF budget, which Keyworth helped shape, also reflects the same approach. While social and behavioral sciences got small increases in the Reagan proposal, the physical sciences, engineering and laboratory equipment got far bigger ones. The life sciences receive more than 40 percent of total federal spending on basic research, and some of those fields have been well treated in previous years. But now, say the social scientists, there is an influence gap developing in the highest science councils.