Christine Penmark (Nancy Kelly) is the daughter of a famous writer, Richard Bravo (Paul Fix). She's married to Kenneth (William Hopper), a military Colonel who seems to spend most of his time away from home, usually on short-term call in some other city. The landlady of their apartment building, Monica Breedlove (Evelyn Varden), is obsessed with psychology, having even been analyzed by Freud. Because of this, she courts friendships with other intellectuals, including a criminology author, Reginald Tasker (Gage Clarke). But by far the most important character is Christine's young daughter, Rhoda (Patricia McCormick).
Rhoda is oddly adult in her behavior. She goes out of her way to excel at everything she does, to be prim and proper, to seem amicable and innocent. However, in the wake of one of Rhoda's classmates falling victim to a drowning accident while on a school picnic, suspicion falls on Rhoda. As more facts come out, Christine realizes with horror that her child just might be a "bad seed".
A tightly focused ensemble piece, heavy on dialogue and taking place primarily in one interior location, The Bad Seed is one of the better but more understated horror films from the 1950s. Because of its ideas, its unusual portrayal of a manipulatively "evil" child (and a weirdly cute young girl at that), and its nihilistic and abruptly mind-blowing ending, The Bad Seed was quite a shocking film in 1956. In my book, it still is. That's not to say that the film is graphic. Much more so than, say, The Haunting (1963), The Bad Seed is the classic example of how something implied and not shown can be just as effective and disturbing as something shown.
Still, not everyone loves it, of course. "Staginess" is often cited with either a direct claim or an implication that that quality is necessarily a flaw. The Bad Seed's "staginess" is easily explicable. It is a film adaptation of a play by Maxwell Anderson, which was itself adapted from William March's last novel, published in 1954. It's easy to see how only minor changes would allow the film to be performed on a stage. However, I don't see The Bad Seed's staginess as a flaw. It's not as if plays are bad merely for the fact that they're plays, right? There seems to be some unspoken or unanalyzed attendant assumption that cinema shouldn't bear strong similarities to other artistic media and/or a belief that cinema should always be "naturalistic". I don't agree with either of those assumptions. Cinema can do many different things. It shouldn't all just be one way or another.
Rather than being a flaw, the staginess of The Bad Seed is an asset. It catalyzed the effective "tell, don't show" attitude towards the film's violence. It allows all attention to be placed on the fantastic ensemble performances, and especially on McCormack, who turns in the best young female performance this side of Dakota Fanning. And it helps make the film feel like the parable that it is.
Under director Mervyn LeRoy's hand, The Bad Seed is an extended meditation on two philosophical ideas--twisted psychologies and the nature versus nurture debate. It's not just Rhoda who has psychologically-rooted problems and dysfunctions, but everyone in the film. Christine is in denial, and shows that she has long been in denial, about her happiness, her life and her daughter. She continually tries to act as if everything is kosher and normal, but as the film progresses, she has periodic cracks in the armor, until the "breakdown" at the end--and even in the midst of that, she tries to act as if everything is okay and mundane. Monica, who keeps trying to psychoanalyze everyone (except the one person she most needs to psychoanalyze), tends to also intellectually browbeat or overpower them. Kenneth is an absentee husband. Leroy Jessup (Henry Jones), the apartment maintenance man, presents himself as just as twisted, deceptive and manipulative as Rhoda, and there is a pedophile subtext with the character. Claudia Fern (Joan Croydon), the head of Rhoda's school, seems on the verge of a nervous breakdown, and also seems to be in denial, as does Christine's father Richard, who also has elements of absenteeism and emotional distancing. Hortense Daigle (Eileen Heckart), the mother of the drowned boy, is an alcoholic, and her tragedy puts her over the edge. In fact, the only character in the entire film who seems well-adjusted is Reginald, and perhaps that's symbolic of his function as a criminologist.
The nature versus nurture material is incorporated in an unusual way. Characters debate this to an extent, but most take the nurture side. However, the film itself makes more of an argument for the nature side, and Christine, despite being in denial, comes to believe the nature side, as does Reginald, the even-keeled character. In fact, William March (the author of the novel) believed more in the nature side, and said as much to colleagues while he was working on the book, including doing research into psychotic killers.
What helps to amp up the disturbing qualities of the film is that Rhoda is manipulating the audience as well as she is manipulating other characters. Only very seldom does LeRoy have her "true nature" come through, and it's a shock to us in the same way that it's a shock to the other characters. The ending of the book was changed to be in line with the "moral code" for Hollywood films at the time, but the resultant, somewhat bizarre ending, is probably more shocking in retrospect than March's original ending would have been. There have been many horror films over the years with endings somewhat similar to March's. There haven't been many that end in quite the same way that The Bad Seed does.
While the film would certainly require a bit of adjustment for many younger modern horror fans, it is well worth watching, especially if you've become acclimated to slower-paced, dramatic, understated horror.