'I AM SAM' HEADS DOWN PREDETERMINED PATH.

Byline: Bob Strauss Film Critic

``I Am Sam'' could have used a lot more thought.

The story of a mentally challenged father's efforts to regain custody of the 7-year-old daughter who's smarter than he is, the film's sole glimpses of considered intelligence rest (admirably) in Sean Penn's precisely observed and calibrated lead performance and (somewhat despicably) in writer-director Jessie Nelson's emotionally blackmailing determination to wring every drop of manipulation out of parental love and holy fool cliches.

Long and loaded from its implausible get-go, the film misses a chance to seriously examine a worthwhile and increasingly common issue: what role the challenged deserve to have in the upbringing of their offspring. Only the most insensitive or cruel bigots - characterized in this movie as, of course, lawyers - could advocate the severing of that most fundamental love connection. But to suggest, as ``I Am Sam'' repeatedly does, that love is the overwhelmingly overriding requirement for navigating the demanding complexities of child-rearing is to insult intelligence in several senses of the term.

Penn's Sam Dawson is a cleanup guy at an L.A. Starbucks. He's sunny and polite enough to be well-liked by customers and co-workers, his minimal IQ notwithstanding. He's able to live on his own, and was also capable, somewhat unbelievably, of fathering a child with a homeless but otherwise unimpaired woman he took in. Mom disappears as soon as she's discharged from the maternity ward, leaving a half-panicked Sam to deal with little Lucy on his own.

Somehow, though - with help from the agoraphobic across the courtyard (Dianne Wiest) and a quartet of differently abled ``video night'' buddies - Sam brings Lucy up to be a bright, happy 7-year-old (played by the energetic Dakota Fanning). But as she realizes that she's starting to surpass her father intellectually, Lucy becomes self-conscious. This leads to a trumped-up crisis and county child services commandeering custody of the girl.

Enter hotshot Century City lawyer Rita Harrison (Michelle Pfeiffer). Unlike Sam, who only freaks when challenges provoke, she's constantly on the edge of hysteria. That's because, as all correct-thinking people know, being a successful female attorney means that your husband will cheat on you, your kid will hate you, and you won't be able to enjoy your Beamer convertible because you're so easily prone to road rage.

Anyway, guileless Sam manages to embarrass Rita into taking his pro bono case. It's a doomed effort, since Sam's a bad witness, all of his friends are even worse in the courtroom and, though it can hardly be acknowledged here, the nasty child services people kind of have a good point.

But Sam's pure love, see, makes his cause just. And being around such uncomplicated goodness makes high-powered Rita reassess and become a better person, too. And ... well, you don't need a compass to figure out where this is all headed.

Penn, an always-smart actor who's consistently proven his worth at playing less-than-brilliant characters, brings a wide range of emotions out of Sam while keeping his actual expressions to a persuasive minimum. It's terrific work that might have made for an outstanding performance had Nelson and her co-writer, Kristine Johnson, had the courage to permit their hero even the smallest, less-than-noble impulse - something that would have made Sam less than a saint, but more of a fully dignified human being.

Faced with the attracting gravity of Penn's technique and Sam's unadulterated sympathy, Pfeiffer has to work extra hard just to hold her end of the screen. The strain often shows, but her spunk is admirable.

It should be mentioned that two of Sam's buddies are played by actors with disabilities, Joseph Rosenberg and Brad Allan Silverman. Though they sometimes, perhaps inevitably, provide comedy relief, their performances are more consistently honest, spontaneous and accomplished than any aspect of the script.

The soundtrack is made up of Beatles songs newly covered by other people. Buy the album, if you must, but bypass the film.

``I AM SAM''

(Rated PG-13: language)

The stars: Sean Penn, Michelle Pfeiffer, Dianne Wiest, Dakota Fanning, Richard Schiff, Laura Dern, Loretta Devine.

Behind the scenes: Directed by Jessie Nelson. Written by Kristine Johnson and Nelson. Produced by Richard Solomon and Nelson. Released by New Line Cinema.

Running time: Two hours, 14 minutes.

Playing: AMC 14, Century City (one week only).

Our rating: Two and one half stars