Most people think they judge a movie by its overall quality, but that might not be true. We might instead judge it by its best scene, and its spectacular ending. And this might explain a few things about movies.
But first, let me tell you a tale. There once was an experiment! This experiment lived in a room with a headset. It invited boys and girls inside the room, and offered them some nice hot informed consent paperwork, a chance to listen to something using the headset, and a terrible choice!
When the boys and girls put on the headset, they heard two awful sounds. One was eight seconds of loud, unpleasant noise. The second eight seconds of loud, unpleasant noise followed immediately by eight seconds of slightly less loud, slightly less unpleasant noise. When the boys and girls had heard both, they were presented with the choice. They would hear one of those sounds. Would hear the eight seconds of miserable noise, or the sixteen seconds of miserable-and-then-less-miserable noise? They chose... unwisely.
They did this because it seems that people don't judge an experience but its overall quality. Instead, they cobble together a judgement based on the peak of the experience and the end of the experience. People were willing to have a longer bad experience as long as part of that experience — specifically the end of the experience — was less bad than its average badness. The same thing was found when study participants were asked to submerge their hands in ice water for a length of time, or in ice water for the same length of time and then slightly warmer ice water. Any slightly better experience, especially towards the end, offset the terrible part of the experience.
This was found to apply to vacations as well. When students went on vacation, they were asked to send a text describing their happiness each day. At the end of the vacation they were asked to rate the overall quality of the vacation. The ratings didn't cluster around the average happiness experienced during the vacation, but by its brightest moments - especially if those bright moments came at the end. Taken together with the data regarding the sound experiments, this pattern garnered a name - the peak-end rule. The rule might explain why people are so willing to, for example, climb Mount Kilimanjaro. Although it involves spending days laboring unhappily without an adequate amount of oxygen, vacationers only judge the experience by how they feel when they're at the top, and the accomplishment they feel at the end.
This evaluation is only tested in labs, and by monitoring vacations, but it may explain a lot of pop culture trends, including movies. Lately both critics and fans have remarked on the running time of films — especially the kind of epics that suit science fiction and fantasy. It's rare to see a 90-minute movie anymore. Most run about two hours, sometimes tipping towards three. When the films are adaptations of books or comics, the biggest complaints that fans have aren't about the running time of the film, they're about how the film left their favorite scenes or characters out. We don't want good stuff, we want a lot of stuff. And when we get it, we'll only remember the best parts.
I find this happens a lot. I enjoy a film and rent the DVD, only to find that it has a long, sluggish beginning, and I really only wanted to see about three scenes and the battle at the end. The way to craft a popular movie, then, is to keep cramming in scene so everyone will enjoy at least part of it, and then finish strong. Hell, there's even a scene in Adaptation, a movie about films and screenwriting, where the wise screenwriting god tells the neurotic young screenwriter that all he has to do is write a great ending to make everyone love his movie.
In most entries about cognitive biases and psychology experiments, the natural response is to think, "I wouldn't do that." In this case, I know I certainly have done that. What about you? While everyone deplores the idea of bloated, unfocused movies, have you caught yourself wading through hours of boring stuff so you can watch those few great scenes — and judging the movie only on those moments of fun?