A willing suspension of disbelief is necessary from the very outset of "A Family Thing," with its unlikely pairing of Robert Duvall and James Earl Jones as brothers. Unfortunately, an improbable premise is not the movie's only problem: despite the weight of its two lead actors, it ultimately fails to achieve any lasting emotional impact.

The film begins after the funeral of Arkansas native Earl Pilcher's (Duvall) mother. In a letter written before her death, she reveals that, although he looks white, Pilcher's real mother was a black woman, a maid forced into a sexual relation with his father. She died after giving birth to Earl, who was afterwards taken into the Pilcher household and brought up as a legitimate son because of his white skin and features. Further, Earl learns that through his natural mother he has a half brother named Ray Murdoch, now a policeman living in Chicago.

Visibly shaken by this revelation, Earl nonetheless finds himself driving up to Chicago in his pickup truck in search of this unknown brother. He eventually tracks down Ray (Jones), who meets him with barely concealed hostility, and the two part with an apparently mutual desire never to see each other again. However, by a quirk of fate, Earl runs into four black youths who rough him up and make off with his wallet and his truck. Against his will, Ray is forced to take Earl temporarily into his own house.

The film is well acted, and Duvall and Jones generate some genuine, tastefully understated chemistry without slipping into sloppy sentiment. Another plus is Irma Hall, who is wonderfully enjoyable as the testy, domineering, but open-minded and warmhearted Aunt T., the sister of Earl and Ray's dead mother. But "A Family Thing" stumbles in its attempt to bring other, cliched themes and subplots into play. Earl's first few days in Chicago, including his night of drunken wandering, are a tired variation on "hillbilly enters the big city," with a few half-hearted efforts at humor and some moments of "racial awareness" that are not sufficiently explored to make them really interesting. Then we encounter the overused theme of an ex-sports star who feels his best days are gone forever: Ray's son Virgil, once a college football star, has become embittered--and estranged from his wife and two daughters--through brooding over the knee injury that wrecked his dreams. It is, of course, up to Earl to teach him to get over himself and go on, and he does so, but not in such a way as to make the audience feel anything at all.

In an interesting but not wholly plausible twist, despite Earl's "white" identity and Southern roots, it is actually he who shakes off his prejudices most easily. Beneath Earl's expressionless facade, he harbors no real racism and sincerely wants to get to know this brother he has never known. Ray's conversion is the true struggle: though outwardly courteous, he holds on to his resentment and his hatred to the very end. An undercurrent of tension therefore remains up to the day of Earl's departure, when Aunt T. shares a secret with them both that dissolves the final barrier between them and binds them together for good.

But this intended moment of epiphany somehow falls flat, spoiled by Aunt T.'s inappropriate exclamation "You were as white as an angel!" In general, the women in "A Family Thing"--Aunt T., Mrs. Pilcher, Ray's and Earl's mother--are too saintly to be true, while the men are either churls (like Pilcher, Sr.) or burdened by a huge chip on the shoulder. Like balky horses, they must be forced into decent, sensible behavior by their womenfolk. "A Family Thing" would probably have been more convincing had nobility and selfishness been more evenly divided between the two sexes.