That's what sets apart one actor from another, and that you can't teach. You can't give someone that. When you're working, putting a character together, or in a scene, that's where things will happen that you have to have the intuition to notice them, and to register them.
You're trying to form this human being that will fit the bill, and the human being becomes a hand, and the research is a glove, and you try to bring this character together into the research, mesh it, and create this person that is the sum total of all that endeavor. Timothy Spall