Writing from the perspective of his villa in the South of France, Puner (author of To the Good Long Life, 1973) has a look, this time, at Americans as they struggle painfully through middle age. By the time the fifties arrive, he notes, 91 percent of us have been married, widowed, or divorced, our I.Q.'s have increased roughly 10 points since our school days, taste buds have withered--except for the ones around the edges of our tongues-shortsightedness has set in, women are menopausal and men in the midst of a ""climateric"" (the male equivalent of menopause, mostly psychological in nature). Everybody, it seems, runs psychologically amok, with women whose children have finally fled the nest showing renewed interest in sex, and men terrified that they can't comply. This is the age group that consumes the self-help books and the leisure suits, since the crisis of middle age is every bit as unsettling as the one that occurs in adolescence. And Puner's effort, though not the most scientific of the help-for-the-middle-aged books, will prove soothing for those who recognize themselves on every page.