22fps is what the human eye sees as natural motion. The two extra frames for film (24fps) are added in in case a frame is dropped during broadcast. The further above that you go the more the game looks like it's put on fast forward (People with VHS should remember what this looks like vividly). 60fps for gaming is a nice sweet spot because you're not that far ahead of natural motion and not too far ahead for it too look like it's getting sped up. This is more useful for gameplay especially when you need it for reaction time. On the flip side; your eyes will adjust to 60 fps and it will eventually seem like 30fps anyways so it doesn't really matter. Though going back to 30fps after will look as weird as something in 60 until your eyes re-adjust.
