Researching his book Star Trek Memories, William Shatner asked Leonard Nimoy how playing Mr. Spock had affected him.
“I was, in a way, in deep isolation, and having a tough time,” Nimoy replied. “The character isolated me, and I think that during the course of a day on the set, I probably projected a certain kind of indifference, intolerance, frigidity, whatever.
“I remember one day we were all sitting around waiting for a set to be lit, and I was sitting there totally stone-faced and out of it. One of our actresses said, ‘Oh-oh, Leonard’s in his Spock bag.’ I was even told one time that one of our producers said, ‘Watch out for Nimoy, he’s a cold, calculating fucker.’
“But this was almost to be expected in that nature abhors a vacuum. When a person shows a personality that seems to be devoid of any clear signal of what he or she is thinking, people project into that whatever they perceive. To some people, I was probably threatening, remote and distant, all of that, I’m sure.
“I actually took great pride in being the only one who was not laughing when a great joke was being told. It just served to confirm that I was successfully staying in character. You know, to make me laugh would have been to suggest that I’m like everybody else. I’m not like everybody else.
“So I prepared to go on stage by getting into character long before it was time to make my entrance. I didn’t believe it was possible to be ‘Person A’ offstage and ‘Person B’ as soon as you got within the sightlines of the camera. I just didn’t believe it was possible. What I did believe in was thorough preparation and maintaining the condition of the character during the lighting, during the scene shifting, during the makeup touch-ups and so forth.
“So I probably was sending off signals of hostility and of being unfeeling, perhaps superior, but that was my intention. And I did all of that because I thought there was a wonderful springboard here, a great opportunity because Bill, as Kirk, was always so energetic in the work, so forthcoming, so definite, even defiant. ‘I’m going to DO THIS! I’ve made up my mind!’ That energy allowed me tremendous opportunities to play reflective. Y’know, McCoy could play the angry quibbling argumentative hand-wringer, ‘Jim, are you CRAZY?!’ and that was great for him. With all that in place, I could play, ‘Hmmm, isn’t that interesting?’ and the relationships worked together wonderfully.’”
Spock didn’t work as well at home, however. Nimoy said he had trouble shedding his Vulcan detachment even on weekends, and probably seemed distant to his wife and kids.