Nerys Myk wrote:
Temper tantrums are part of some classic Spock scenes in TOS.
Which Nimoy disavows in interviews as him "finding" the character. Those scenes are in the can and you can retcon it if you want, but it wasn't how they originally planned him.
Spock from TOS seasons 1-3 was the character of Number One from "The Cage" applied to Nimoy. In the earliest plans for Trek, he had red skin and had a metal plate on his chest through which he absorbed energy.
TOS was always finding excuses for Spock to get emotional or fall in love or go nuts (Naked Time, Shore Leave, Amok Time, Enterprise Incident etc). It's what made him interesting, getting glimpses of what lies under that Vulcan mask. This film manages to work it into a plausible context (the secret affair with Uhura because he's a "closeted emotional", he attacks Kirk because he's reached the breaking point after an unimaginable tragedy etc) without resorting to the tricks the TOS episodes had to to ensure he'd be back to normal by the end.
But of course if you don't count the episodes where we see Spock's guard comes down...