A Harvard Faculty expert on civil rights said yesterday that the Senate bill to establish a sixth grade education as sufficient proof of voting literacy would represent, if passed, the strongest 'Negro voting' measure since the 14th and 15th Amendments.

Introduced on January 20 into the upper house, the Mansfield-Dirksen bill would wipe out all state literacy tests, a major device now used by some Southern states to keep Negroes off the voting rolls.

Thomas F. Pettigrew, associate professor of Social Psychology, called the literacy system "a serious handicap" to the would-be Negro voter. He predicted that "if the bill goes through, and is strictly enforced, we can expect a rise from 1.5 million to 3 million registered Negro voters in the South by 1968."

"The sixth grade standard is not as arbitrary as you might think," he added. "You 'll notice the Negro leaders are subscribing to it without hesitation. The fact is the young and middle-aged form the bulk of the Negro voters--and these groups have had a sixth grade education."

The bill wouldn't have had nearly as much force in 1950, he claimed, because at that time the median number of years of Negro education was much lower. In 1950, Mississippi had a median of five years; at present the figure is between six and seven years, with the elderly Negro group holding the median down. Not greatly affected by the bill, this elderly group is an unimportant target anyway, explained Pettigrew, because "it is a product of the lynching period and not very disposed to vote."

The tremendous expansion in Southern Negro education which gives the Senate bill its potency is "a great irony to the South," according to Pettigrew. The South began serious attempts to educate Negroes in the late forties when Supreme Court investigations of the "separate but equal" doctrine threatened the segregation of the school system.

Conditions in Negro schools were vastly improved, noted Pettigrew, only to be followed in 1954 by the desegregation decision. And the South's belated efforts "have only given birth to the sit-in generation, and allowed the bulk of the voting-age Negroes to come under the proposed literacy qualification."

The Mansfield-Dirksen bill would be far more effective than the two Civil Rights Acts of 1957 and 1960, Pettigrew said. While the two acts, which provided for federal injunctive action where voting discrimination is spotted, have not had spectacular results, "a rise of "a million and a half among Negro voters if this bill is passed would be no pipe dream."

Tracing the development of the Negro vote since the Depression, Pettigrew said the first significant rise in the vote occurred after the 1944 Supreme Court decision abolishing the white primary. As a result, Negro registered voting jumped from 1/4 million in 1940 to 3/4 million in 1946.

Pettigrew attributed the increase of almost a million since 1946 largely to practicing Jess discrimination.