Trivia: Every time dead people are close by, there is something red in the preceding scene (i.e., when Cole is at the birthday party and is about to get trapped in the attic with the ghosts, there is a red balloon rising toward the ceiling; when Graham comes home to his wife sleeping and is about to realize that he too is dead, she is wearing a red throw; when Cole is in the car with his mother and there is an accident up ahead, she is wearing a red sweater, etc).
Trivia: The doctor that treats Cole after the incident at the birthday party is played by director M. Night Shamalyan. Interesting about this scene is that Shamalyan came from a family of doctors, including his wife who is one. He also at one time wanted to become a doctor before he decided on a career in filmmaking.
Trivia: The first draft was very different. Malcolm was a world-weary forensic photographer working on a serial killer case, and Cole was his son. When Malcolm discovers that his son can see dead people, they would team up to have Cole speak with the ghosts of the killer's victims to try to figure out who the killer was. It was very much a police thriller... just with a supernatural twist. Writer/director M. Night Shyamalan completely overhauled the story into a horror-drama during multiple rewrites.
Trivia: Part of the reason Haley Joel Osment won his part was because he impressed director M. Night Shyamalan during the audition with his dedication to the movie - he mentioned offhand that he "read it three times last night." Shyamalan asked if he meant his lines... to which Osment replied that no, he read the entire script front-to-back three times the night before.
Trivia: If you pay attention, there's a nice subtle detail... you can see that both Vincent and Cole have white patches in their hair. While it has never been definitively proven, there is a belief that periods of extreme stress or fear can affect hair pigmentation and make it turn white. One study actually did observe the effect in mice that were placed in high-stress situations for periods of time. Since Vincent and Cole are both terrified of the ghosts they see, they have similar white patches.
Trivia: Toni Collette reportedly didn't realise the movie was a horror film until she finally saw a cut of it. She was so emotionally affected by the script and her character, she assumed it was a straight-up drama with a supernatural twist. When she finally saw the movie, she realised how scary it was.