Where is the satisfaction in being forced to jump out of our skins as someone or something leaps out at the least obvious moment? Why do we do it to ourselves? Is it a battle of wills between us and the director to see whether he can make you actually make you physically shit yourselves?
Or it that same impulse that when someone tells you to smell something bad, you can't help but do it? It's OK, we've all done it. Whatever the reason, some directors have certainly succeeded where others have failed by making you actually lift off out of your seat.They can almost be measured by the sound of everyone landing. And here are the best, with video…
9. The Bourne Identity
We're not sure what's more shocking, the moment the guy comes through the window or the fact he commits suicide by deliberately jumping back through it.
We are going to need a bigger boat. It's possibly the defining moment of the film, as Brody suddenly gets his first good look at the shark while chumming.
7. Deep Blue Sea
If anyone ever tells you they knew that a flying shark was about to come and bite Samuel L Jackson in half they are simply lying.
No, we don't want to hear it. Liars, the lot of you.
6. The Thing
OK, it may not make you jump out of your skin, but it certainly shocked us. Just didn't see it coming.
All right, it's hardly shocking now because we all know what happens, but remember the first time you saw it.
If you're not convinced, just look at the actors' reactions. They had no idea what was going to happen. Brilliant!!
4. Friday 13th – Part 1
Just when you thought it was safe to put the cushion that you'd welded to your face throughout the movie down, there is another bloody shock as Jason suddenly re-appears from under the water to knock off the remaining survivor. A million sequels are spawned.
3. Jaws – The head
It doesn't matter how many times we see this, we still jump at that stupid head coming out.
Surely one of the biggest jumps ever, as Carrie's blood-soaked hand comes out of her grave and grabs the hand of a terrified Amy Irving.
If you did not jump at the moment when we realise the Sloth guy is not actually dead you must be dead yourself. We think our bowels loosened for a brief moment. There should be a law against it.