Marston Bates has subtitled his book ""The Human Problems of Being Natural."" Actually; he considers that ""there is nothing natural left in human behavior--it is all governed or modified in varying degree by culture, tradition, opinion."" To pursue his point, he explores the customs surrounding food and sex. Why three square meals a day instead of six less square ones? why not insects for food? we eat the product, honey. What is behind the taboo on incest and the practice of cannibalism? Cultural Values. Man is aggressive (and the question of Whether war is natural is irrelevant). He wears clothes--for identification, ornament, provocation and protection. He forms suo-and-contra- cultures (Skid Row is sub, but where do prostitutes belong?), repairs to priests and policemen, strives for Utopia. ""I suppose this whole book is a plea for the tolerance of diversity,"" says Bates in closing. It is also an entertaining exercise in delineating homo not so sapiens.