According to biographer Scott Eyman, Stewart was an instinctive actor. He was natural and at ease in front of the camera, despite his shy off-screen personality. In line with his natural and conversational acting style, Stewart's costars found him easy to work with as he was willing to improvise around any situation that arose while filming. Later in his career, Stewart began to resent his reputation of having a "natural" acting technique. He asserted that there wasn't anything natural about standing on a sound stage in front of lights and cameras while acting out a scene.