Social psyhologist Kenneth B. Clark, a long-time student of American race relations, said yesterday that before further desegregation will occur in Northern urban schools large numbers of whites must realize that racially segregated schools are as damaging to their children as to blacks.

"Those of us who still persist in the quest for racial justice must now begin to emphasize the fact that segregated schools are an anachronism in the latter part of the 20th century," Clark told a Howard University Law School conference commemorating yesterday's 25th anniversary of the Supreme Court's decision banning racially segregated schools.

Clark, whose research helped shape the Supreme Court ruling in the Brown vs. Board of Education case, said effective ways must be found to tell "the general public that white children who are being isolated in redominantly white schools are not being protected."

"Racially homogeneous schools reinforce irrational fears and hatreds, tribalisms and parochialisms and social ignorance and superstitions," Clark said. "Educated under these conditions, these 'privileged' children are made awkward and inept and unable to function effectively when required to interact with others who differ from themselves in superficial physical charecteristics."

Clark, whose controversial plan for improving reading skills was adopted by the Washington school system in the early 1970s and then largely abandoned, said the problem of racially segregated schools in Northern cities is much more difficult to change than the legally sanctioned segregation that once existed in the South.

"Northern protectors of the racial status quo come armed with sophisticated and sometimes subtle intellectual arguments," Clark said. "They seek to support the maintenance of segregated schools by such diversionary issues as busing, the sanctity of neighborhood schools and preoccupation with the desires of white parents to maintain the integrity of 'their schools' in order to prevent 'white flight.'"

Nonetheless, Clark said, "It remains a fact that segregated schools in the North are as dmaging to human beings as ere the (legally sanctioned) segregated schools of the South.

"In spite of a few exceptions to the contrary, segregated schools to which black children are relegated are perceived as inferior, tend to function in terms of inferior standards, are stigmatized, overtly or implicitly, and are characterized by low morale and aspirations on the part of students," Clark said.