When I first started as a designer, I thought frequently about experiences that were well-designed compared to those that were not, and how the outcome differed. What was the value of design? For example, when I click a button and expect a drop down menu to appear, I feel cognitive dissonance when the menu suddenly appears. When the menu slides out however, I feel more at ease. When I use a UI with a lot of jump-cuts (a la things suddenly appearing) my brain has to pretend that all the in-between frames are there. When we use interfaces that actually animate all those in-between frames, however, we can take a shortcut through our visual cortex. The change in interface no longer disrupts the main task.
Think of the human brain like a computer. You have first, a main thread, and second, a GPU – a graphics processing unit in your visual cortex. You can feed people a lot of information through their visual cortex without interrupting what they’re thinking about. Animation allows the user to continue thinking. Imagine using your smartphone without animations. It would be like a tap and jump cut for everything you do. Would you have still bought it?*