The best way I know to look at it is this:
Take a piece of fishing line, pull it tight between your hands and have someone pluck it. Now, take a rubber band and do the same.
The rubber band obviously transmits a lot more vibration, because it's much more elastic. That's the simplified version of the way string vibration works.
It doesn't have to be a "skinny" string, and it doesn't have to be endless, although you might (or might not) notice a slight difference between them--you might even get more with skinny, depending on the material, because it's going to have more stretch.
I've never shot a bow that had as much shock with a FF type string as it did with dacron. Re-tuning is required when swapping strings to get the best results.