THEIR PRIDE AND JOY<i> by Paul Buttenwieser (Laurel / Dell Publishing: $8.95) </i>

The Gutheim family (whose name means good home in German) carries the burden of the noblesse oblige with grace: giving money to orphanages; keeping a box at the Metropolitan Opera House; shopping only at Bergdorf’s. As the youngest son, Carl, says: “You know how it is with this family. If you’re a lawyer, you make the Supreme Court. If you’re a tennis player, you win the Davis Cup. If you’re a pianist, you play in Carnegie Hall. . . . There’s no room for mediocrity.”

But daughter Joan shows some signs of imperfection: She passes out while walking from the dining hall to her dorm during her senior year at Bennington. Her mother, Peggy, insists that Joan return home for a medical diagnosis. But not even the specialist Peggy hires can bring himself to name Joan’s “difficulty”: anorexia nervosa.

Peggy arranges for Joan to work at a settlement house and is certain that this opportunity to be useful will set Joan back on track. In fact, Joan’s affair with a fellow worker, Kevin--an attractive, uninhibited, reformed street tough--brings her to the height of sexual passion as it brings her downfall.