The movie is not cinematic perfect. The child actor has little screen presences and the scenes with him don't always work well. So what? This is a film about ideas and in that this film succeeds brilliantly. Brian Keith and Kim Hunter turn in fine performances as does Bette Davis.
This is a movie on Davis' resume that I always just unintentionally skipped over in my head for some reason, but your review has piqued my curiosity.