Perhaps it is because British actors can actually act?

"How do you know when an actor is not acting?"

Some of us want actors to act, not burst into song every time there is an emotion.

The actors barely act, since they do not speak to one another, and almost never face the camera.

The actor in this case a cop is acting under color of state law, but presumably with a defense.

One of the reasons we go to the theater, after all, is to watch actors act.

In Washington, at any rate, people are starting to act as they see actors act.

In a representational play, the actors all act as if there were a fourth wall between them and the audience.

The actor knows he or she is being watched and acts accordingly.

He was trying to get actors to act against the emotion.