The horror equation

Australia's The Age has an interview with American Nightmare documentarian Adam Simon about the ebb and flow of U.S. horror films. It's a decent enough article. But scroll past that and you'll find a curious little item titled "The horror formula." It sounds vaguely familiar, but it may be worth repeating.

British researchers from King's College have figured out a mathematical formula that identifies the most effective way to induce terror in a film: (es + u + cs + t) squared + s + (tl + f) / 2 + (a + dr + fs) / n + sin x - 1. Suspense and realism, the equation shows, are among the key ingredients for a chilling movie.

They found that suspense is primarily generated through escalating music (es) the unknown (u), chase scenes (cs) and the sense of being trapped (t). Because suspense is such a vital quality in a horror movie, the equation is (es + u + cs + t) squared before shock (s) is added.

The Shining, in which the suspense builds gradually through a child's eerie premonitions, was held up as the perfect example of the formula applied.

The experts argue that realism intensifies the mood of anxiety. Therefore the next part of the model adds together true life (tl) and fantasy (f) divided by two (tl+f)/2 to establish the right balance between a plot that is too unrealistic and one that is too mundane.

The smaller the number of characters (a) in the film, the more an audience can identify with them. A darkly lit scene (dr) and an isolated setting (fs) also raise levels of fear. But stereotypical characters (1) diminish the effect and it is actually possible to have too much gore (sin x).