This, from The Making of Star Trek (1968):
Because of who he was, Spock in TOS was also the "uber-Vulcan," who believed he had to be more Vulcan than a Vulcan. There's very little reason for Spock in the new universe to feel that way, any more. He's becoming at peace with his emotional side differently, and more quickly, than Spock Prime did.
That's from the author, Stephen E. Whitfield. Here's a quote about Spock from Roddenberry, who contributed to the book:Because of his mother's origin, however, Spock does have a human side to his personality. A human side with emotions. The result is a continual struggle within himself to suppress his feelings. But the Vulcan half is normally in control. Conditioned since childhood not only to deny but also to be ashamed of emotion, Spock thrusts feelings aside and finds a "logical" rationalization to explain it.
Here's Nimoy in the same book:Which is one of the reasons why Spock is an interesting character. The turmoil and conflict within. As half-human and half-Vulcan, he is continually at war with himself.
Seems nothing about Spock occasionally showing emotion (delighted by a plant, upset at the disappearance of THE WOMEN) is really out of character. It may be unusual, but not out of character.Spock is fun to portray, because underneath, he really does have emotions. ... Actually, Spock has a considerable amount of compassion...."
Because of who he was, Spock in TOS was also the "uber-Vulcan," who believed he had to be more Vulcan than a Vulcan. There's very little reason for Spock in the new universe to feel that way, any more. He's becoming at peace with his emotional side differently, and more quickly, than Spock Prime did.