When I was a kid, I went to the local Salvation Army store and bought "The Amityville Horror" in paperback. I was a huge Stephen King fan and wanted to read more scary stories. The book was filled with disclaimers, interviews, and floorplans of the house and property. I was scared to death after reading the book, bascially because I believed the story to be completely true. Paranormal Activity is one of those handheld camera movies that relies on the inferences from the movie maker that the events are true.
Like Blair Witch and Quarantine before it, Paranormal Activity uses the handheld camera techniques by the amateur participants in the movies to sell to us, the audience, that everything we are witnessing is real. The editor of the film even forsakes the titles and credits in favor of a "thank you" message to the families of Micah, Katie and the police department. If you believe, this movie is even better.
For the rest of us, prepare for the slow building and unfolding of the story and the history of the characters. Soon doors start to swing by themselves, off-camera thuds manage to startle us, and the events start to become more ominous. All of this prepares us for the last 20 minutes where us voyeurs finally get the payoff we were waiting for. I expected where the last 5 minutes were headed (no spoilers here) but even I did not see the last two minutes coming at me until it was too late.
All in all, I applaud the moviemakers for showing us that thuds and booms can be scary, even when there is not a soundtrack effect to tell us how to react. I also enjoyed that they took the high road and did not use the obvious scares. Case in point is the attic scene... we have become so accustomed to getting scared when checking out attics (The Grudge, Quarantine) that we automatically brace ourselves against the fear.
Worth: Matinee and a DVD