What Is The Origin Of The Infamous Gibbs Slap On NCIS?

If you've been watching NCIS for a while, you've seen it. Leroy Jethro Gibbs, played by Mark Harmon, slaps someone upside the head for saying something stupid or going off-track. You're not the only one who's noticed — it's a whole thing. The "Headslap" even has its own page on the fan-run NCIS Database, and you can find YouTube compilations of times when Gibbs lost patience and head-slapped someone, when others imitated Gibbs and head-slapped someone else, or when they saved Gibbs the trouble and slapped themselves. In general, though, the Gibbs slap is an admonition that was reserved for Anthony DiNozzo (Michael Weatherly).

The first incidence of the patented Gibbs head slap took place during the first-season story "The Curse," naturally, between Gibbs and Tony. DiNozzo refers to an earlier moment in the episode as the two peer at a computer screen, telling Gibbs, "Don't strain your eyes, boss." Later, the head slap even became a plot point — it was revealed in flashbacks during season 3's "Hiatus, Part 1" that Gibbs learned the move from his predecessor, and he's clearly been passing it to his own employees.

Gibbs famously said in the season 2 episode "The Bone Yard," "A slap in the face would be humiliating. Back of the head's a wake-up call." But how did this come about, anyway? Is the Gibbs slap something that was scripted in? That seems ... unlikely. Over the years, through interviews, the actors have revealed the behind-the-scenes scoop regarding how the Gibbs slap came to be. 

In an interview from Festival de Television de Monte Carlo in 2010, as reported on by Showbiz CheatSheet, Mark Harmon talked about the first time he ever did the Gibbs slap to Michael Weatherly, cementing the move in NCIS history.

"Michael is a hugely talented actor, as is every member of this cast," he said. "My memory of when that happened, we were doing a scene, and he was on a Navy ship and he was talking to a female petty officer. I think this was in year one, early. And he was doing what he does, which is sometimes stay on script, sometimes not [...] I just reached over and smacked him, tried to put him back on line. It was an instinct. It wasn't thought. I didn't think about it, I just did it." 

So, it was an impromptu moment, showing that Harmon isn't too far-removed from his on-screen character in terms of getting impatient with his co-workers. Although the back-of-the-head slap was meant as a warning, Gibbs goes on to praise his fellow actors.

"To his credit, he stayed in the scene; he didn't break. And I didn't break," Harmon said. "And the girl in the scene playing the petty officer, she was shocked, she was surprised. And she stayed there, and we just kept going. And people liked it. And so then every episode I was smacking him — maybe too much. We still do that occasionally, but we do it sparingly. [...] That's where it came from."

Michael Weatherly's story is similar. He said in his interview with Festival de Television de Monte Carlo, "I had a dialogue with an actor; maybe it was episode 3 or 4, season 1. And I was in the background and I didn't have any dialogue. So, I was whispering to a girl who was working in the background of the set... And all of a sudden, [Mark Harmon] came over and hit me on the back of the head. And everyone was shocked. And they printed it. So, the producers [...] saw the footage. They laughed, because it was funny. Although it wasn't really funny to anyone who was there that day 'cause I was in trouble. And it just became part of the show."

Weatherly has more to say on the subject, though. He talked to USA Today about the Gibbs slap, pointing out that Harmon was a college football player and has a very strong throwing arm. "So there was a certain degree of speed that would take place," the actor said. "When you watch [the slap], it only happens once. But when we shoot it, as you are well-aware, we might do it 30 or 40 times." Ouch. 

Tony DiNozzo left the show at the end of Season 13 — and the head slap, for the most part, went with him. His replacement, Nick Torres (Wilmer Valderrama), doesn't have the same kind of relationship with Gibbs that Tony did, so a similar, familiar gesture like that wouldn't have felt quite right as the new guy was getting his bearings. Valderrama revealed at a 2017 TV Guide's Fan Favorites panel during San Diego Comic-Con (via FanSided) that prior to his first appearance on the show, he felt that way, at least: "I think we're going to develop our own little thing; the slap is Tony's."