The East Germans -- close up; Twelve Years: An American Boyhood in East Germany, by Joel Agee. New York: Farrar, Straus & Giroux Inc. $14.95.

The East Germans -- to me at least - have never emerged as a people. Thanks to the image their government tries to project, I see them as a gray, disciplined mass. Now along comes Joel Agee, who has lived among them, in a sense been one of them, to give faces to the faceless.

Joel's mother had left his father, James Agee the writer, married a German Communist, and moved to the village of Gross-Glienicke. There (and in East Berlin) Joel grew up as a German, thought as a German, and, when he rebelled, rebelled not against communism as such, but, like young intellectuals everywhere , against authority. His American citizenship went almost unnoticed by him and by his peers.

Unfortunately he seems more concerned with sharing his not-very-original preoccupation with sex than filling in our blanks about East Germany. He doesn't even spare us his fantasies. But readers willing to do a considerable amount of skipping will discover that, after all, he has given the people individuality and their countrys ide character.