How Leonard Nimoy Came Up With Spock's Vulcan Nerve Pinch On Star Trek
The first appearance of the now-famed Vulcan nerve pinch was in the "Star Trek" episode "The Enemy Within" (October 6, 1966), wherein Spock (Leonard Nimoy) used it to incapacitate en evil duplicate of Captain Kirk (William Shatner). The nerve pinch was evidently so exactly placed on a victim's neck, and so strongly squeezed by the perpetrator, that it would induce almost instant unconsciousness. Rowdy Trekkie kids witnessed the nerve pinch and likely tried it out in their siblings, much to the consternation of their parents. No, kids, the Vulcan nerve pinch doesn't work in real life.
Nimoy himself invented the idea for the Vulcan nerve pinch. The multi-hyphenate, it seems, didn't like the violence that the "Enemy Within" script called for. It read that Spock "kayoes" Kirk (as in K.O.s, as in knocks out), by hitting him in the head with the butt of his phaser. Nimoy, however, was a pacifist, and didn't appreciate that. He felt that his collected and logical Vulcan character wouldn't have the wherewithal to smash a guy in the head with his gun. Instead, Nimoy invented an equally dramatically satisfying way to incapacitate an attacker by merely pinching a nerve on their neck. The idea was that Spock, an immensely intelligent person, would know all about human anatomy and could use that knowledge to his advantage in a fight.
Back in 1969, Nimoy was on the Canadian interview series "The Day It Is" (an appearance covered by the CBC website), and he explained in greater detail how he came up with the nerve pinch, and why he felt it was necessary. Most notably, Nimoy felt that a pistolwhip seemed dated in the idealistic future of "Star Trek."
Leonard Nimoy felt that pistolwhip was 'archaic'
When the day came to shoot the pistolwhip scene, Nimoy objected and spoke to the episode's director, Leo Penn. Nimoy felt that he and the director should have creative leeway with Spock, as his alien culture could be invented on the fly. In his own words:
"I said to the director: This is archaic. This is really Western, you know, to pull a gun and hit a guy on the head from behind. [...] This man is an alien, we don't know anything about aliens. We can say anything we want, we can make the audience believe anything we want about an alien. [...] Let's use our imaginations. The man could have a very special knowledge of the human anatomy that hasn't been discovered yet, or he may have some special power that only Vulcans have."
Trekkies have suggested that because Vulcans can engage in touch-based psychic links (mind melds), they might be using a mild form of their psychic powers to incapacitate attackers. This, however, was later refuted when other non-Vulcan characters (such as the android Data on "Star Trek: The Next Generation") also performed Vulcan nerve pinches. These days, it's more widely accepted that the Vulcan nerve pinch is an advanced form of aggressive acupressure, using a human's nerve bundles against them.
There was even a line of dialogue in the episode "The Omega Glory" (March 1, 1968) wherein Kirk complained that Spock hasn't been able to teach him how to execute a perfect nerve pinch. Spock replied that he tried to once, but the lessons didn't take. It seems that performing a Vulcan nerve pinch is merely a matter of mastering a skill.
The producers of Star Trek liked the nerve pinch
Nimoy and Leo Penn shot the neck pinch, and the footage made its way to the higher-ups. Luckily, the producers liked how unique the pinch was and decided to incorporate it into more and more scripts. As Nimoy recalled:
"Producers saw it in the rushes — the dailies — the next day and said: 'That's a great idea. Let's keep using that.' [...] It became kind of a traditional thing, and we had great fun with it. And I avoided what I consider physical violence ... it was a merciful way of knocking out an enemy."
The Vulcan nerve pinch has since become a sweeping element of "Star Trek" lore, and is still being used on newer "Star Trek" shows. The Vulcan T'Pol (Jolene Blalock) used it on "Star Trek: Enterprise," while Michael Burnham (Sonequa Martin-Green), a human character raised by Vulcans, used the pinch a few times in the series "Star Trek: Discovery." The rebooted Kelvin-verse "Star Trek" films even saw an alternate timeline version of Spock (Zachary Quinto) use it on an attacker.
In the book "The Making of Star Trek," show creator Gene Roddenberry referred to the gesture as the Spock Pinch, and explained, rather simply, that Spock wasn't just compressing a nerve but pinching close the carotid artery, restricting blood flow to the brain.
That makes basic biological sense. Although it still won't work on your siblings, so please do not try.