I’d like to add to the list of things I never want to see in another movie, right after lip-synching to Motown songs shown as a bonding experience and sign of inner hipness, anyone ever saying to anyone, “I got more from you than you ever will from me.”

I don’t mind too much when people feel that way in movies, but when they have to say it, it is a pretty good sign that the film-makers are so uncertain that the formula is working that they just want to make sure we get the picture by spelling it out for us. In movies like this, that’s a clear signal that we’re in the land of “minority or disabled people as magical healers,” and that is never a healthy place to be for too long.

But great actors love great challenges (just look at how many Oscar winners played people with disabilities), so we find ourselves with many opportunities to go there. Sean Penn is a fine actor with a first-rate performance here as Sam Dawson, a retarded man who wipes the tables at Starbucks and wants to fight for custody of his daughter. Fellow star Michelle Pfeiffer has less to work with than she did as a similar character in “One Fine Day,” but manages a good fake smile and a nice crying scene. In smaller parts, Diane Wiest, Richard Schiff, Mary Steenburgen, and Laura Dern are all very fine as well, and the soundtrack of Beatles songs recorded by some of today’s best artists, is a genuine treat. The real miracle of the movie, though, is tiny Dakota Fanning as Sam’s daughter Lucy Diamond Dawson (named for the Beatles song). She gives a performance of such sincerity, subtlety, and delicacy that she almost carries the entire movie herself.

Although Lucy’s mother, a homeless woman, leaves right after Lucy is born, Sam does just fine at first, with help from an agoraphobic neighbor (Wiest) who explains when Lucy is a newborn that Sam should put on Nickelodeon and feed her when “Hogan’s Heroes” is on and then again at “I Dream of Jeannie.” Sam also gets some help from an entourage of retarded pals, and all goes along pretty well until Lucy, at age seven, begins to surpass Sam intellectually.

Then the big, bad wolf, in the form of Family Protective Services (Loretta Devine and West Wing’s Richard Schiff) try to take her away. Sam picks lawyer Rita Harrison (Michelle Pfeiffer) out of the phone book because her name is Beatle-ish. Rita turns out to be a driven perfectionist who gets her cardio in by racing up the 26 flights to her office screaming into her cell phone but snarfs down marshmallows and jelly beans when she feels vulnerable. At first she turns Sam down, but later, shamed into taking on a pro bono case, she agrees to represent him. And sure enough, she learns from Sam to take time to smell the roses and play with her own son. Even would-be adoptive mother Laura Dern, in what amounts to almost a tribute to Sam’s favorite movie, “Kramer vs. Kramer,” shows up in the middle of the night to cry about what a loving father he is.

If only they had trusted the material and the audience a little more, this would not feel so manipulative and dishonest. But by making anyone who thinks that maybe a child needs more than a retarded parent can provide look like a monster, they turn the characters into cardboard. The glowing last scene, with Sam performng in a role that is clearly beyond what he has been shown to be capable of, is just phoney. Yeah, I cried, but I was annoyed about it.

Parents should know that this movie has the requisite one f-word, now standard in PG-13 movies, and some other mild language. There is a stong reference to adultery. Lucy’s mother is a homeless woman who deserts her after she is born. Some children (and adults) will find the custody conflicts and discussion of parenting issues upsetting.

Families who see this movie should talk about what Sam should do to give Lucy everything she needs. What problems are they likely to have as she gets older? What did Rita learn from Sam, and why was it only Sam who could teach it to her? A number of the people in the movie struggle with parenting issues — there has never been a court proceeding in history that permitted such discussion of the family lives of all the participants and witnesses. How do you see those struggles in the families around you?

Families who enjoy this movie will also enjoy Kramer vs. Kramer and Rain Man. They should also read the wonderful Expecting Adam by Martha Beck.