Arm drop speed

I've been playing with this and watching the tutorials  but can't find an answer to this.

When I import a character from Illustrator and drag around the arms in record mode, when I let go of the handles the arms smoothly move back into place. When I rig the arms and move with the handles, upon letting go of the handle the arm snaps back into position.

How do you get the arm to smoothly move back into position rather than snap back when the arms have been rigged?