A whole decade has now passed since we were introduced to the temperamental emotions inside the mind of an 11-year-old girl in Pixar’s Inside Out. When young Riley Andersen’s life is uprooted to move with her family to San Francisco, Joy, Fear, Disgust, Anger and Sadness help her navigate the challenges of a new home, school and life all at once. Voiced perfectly by a stellar cast including Amy Poehler, Bill Hader and Mindy Kaling, the movie was a huge hit with audiences and critics alike thanks to its clever storytelling, unique sense of humour and emotional depth. With plenty of tear-jerking moments and heartwarming lessons about understanding our feelings, we’re still wondering just who gave a kids’ animated movie the right to be that deep even 10 years later. To celebrate the beloved animated film’s anniversary, here are 11 behind-the-scenes facts you probably never knew about how it was made… Inside Out is actually all based on science For a movie about the neurological complexities of the human brain, it was essential to have some professionals on board. American professor of psychology Dr Dacher Keltner worked alongside psychologists Paul Ekman and Lisa Damour as consultants on the movie, along with its sequel, which came out to huge acclaim in 2024. “I’ve taught a human emotion course for 30 years at Berkeley – it’s my pride and joy,” Dr Dacher shared in an interview with Time ahead of the second film’s release. He explained that director and co-writer Pete Docter had reached out after viewing one of his recordings on the topic. “One day, he called me out of the blue and said, ‘Hey man, I’m thinking about making a movie about emotions. Come on down.’ It went so well that he called me again for Inside Out 2…” There were a few extra emotions that didn’t end up making it into Inside Out According to director Pete, there were so many emotions considered at one point that he even wrote an early scene in the film depicting a waiting room for all of them. “There is no scientific consensus about how many emotions there are,” he told The Hollywood Reporter. “At one point, we fooled around with having 27 different emotions.” Eventually, though, they whittled it down to the five we see in the finished film. Inside Out’s emotion characters all had different names at one point In the version of the film that we know and love, each of the characters are named after their individual emotion that they represent. But there was a time where they had their own names. According to The Hollywood Reporter, Sadness was, at one point, called Misty, while Anger and Fear were known as Ira and Freddie. Director Pete elaborated on why they decided against this in an interview with the blog Movie Freak, explaining: “I felt if you called them Sadness, if you called them Anger, then the subtext becomes the text and that’s not a good place to be as a writer. You always want to have a couple layers to things.” He continued: “Turns out, that was confusing to people. I was wrong on that. But, also, early on I think we made them [the characters] pretty one-note. We had to give complexity and nuance to them, especially with Joy.” Designing the emotions proved to be one of the biggest challenges for the Inside Out team Each emotion in the movie is portrayed exactly how you would expect them to look if they were real people – so it’s no surprise a great deal of thought and time went into designing them. “For those of us that lived it,” Pete told USA Today, “this has been literally years and years of trying different things before we arrived where we did.” After thousands of concept drawings, the director noted that “if we did our jobs right, we could really represent these emotions for people,” adding that people “could imagine these characters when they feel a certain emotion”. The outlet also published some of the concept drawings, revealing that one of the biggest questions was whether Disgust should look disgusted or, indeed, be disgusting to look at. In terms of visualising the emotions in the first place, Doctor explained to Screen Rant: “There are things like what we say when we’re feeling sad – we say, ‘I feel blue’. There’s little clues like that, or ‘explode in anger’, those kinds of turns of phrases.” It helped to first picture them as shapes Pete explained in an interview with FX Guide how the team designed each of the characters as shapes. Anger is a block, Fear resembles a raw nerve, sadness is like an upside down teardrop, Disgust is based on a piece of broccoli and Joy is a star. “The look and design of the Emotions had to remind people that they are personifications of feelings,” Pete explained . “They’re not little people. They’re Emotions. They’re made of energy – they’re made up of thousands of particles, which kind of looks like energy. We wanted to capture what emotions feel like – the shapes, the colours – as well as their personalities.” Artist Albert Lozano also shared the inspiration for the characters’ shapes in a video interview with Variety months after the film’s release: One cast member’s initial reaction to the script caused a breakthrough moment During an interview with NPR, Pete explained that The Office star Mindy Kaling was “pretty key to decoding some elements of the story”. He explained that the team were “wrestling” with themes of growing up and embracing sadness, and how the two could be connected. But it was Mindy’s reaction to the story pitch that helped connect the dots. “She really responded emotionally and she said, ‘Sorry, I just think it’s really beautiful that you guys are making a story that tells kids that it’s difficult to grow up and it’s OK to be sad about it’. We were like, ‘Quick! Write that down.’ Because that was really what we were trying to say.” Some other cast members helped develop the story, too In the movie’s closing credits, additional dialogue and story credits are given to Amy Poehler and Bill Hader, with Pete revealing to Movie Freak that they were involved in some of the writing process, too. “In both their cases, they sat at a writing table with us trying to figure this film out,” he shared. “In Bill’s case, I think he worked with us for close to a week and a half. He would sit in the writer’s room, discuss things with co-writer [Josh] Cooley, pace around and touch up sequences. “A lot of stuff that didn’t seem huge but really was, they’d come up with something around that.” With their comedic backgrounds, they also helped inject some much-needed humour into some of the scenes. “We just sat in the hotel room and went through the whole script. The structure was all there but she just kept finding all these places to add things, making it funnier but also finding ways to make it more emotional, give it additional depth.” Director Pete Docter’s daughter was another big inspiration for Inside Out When it came to the concept of the film, the director tapped into his real life experiences as a parent. Specifically, he looked back at a picture of his daughter “being all goofy and she’s got a broken arm and she’s making a funny face”, and compared it to another photo when she turned 11, where her expression was more “ugh”. He elaborated to Screen Rant: “As a parent, it was really tough, because you don’t want your kid to be sad. Also, personally, I really value the sort of goofy, funny play on the ground with dolls and stuff. That’s gone away. That’s not going to be a part of my life anymore. “The story is kind of told from a parent’s point of view, Joy being this surrogate parent. Trying to figure out what’s going on in our kids’ heads is what led to this movie.” Inside Out took over five years to make It’s no secret that animated films take many, many years to create. This one took about five and a half years. “Animation is glacial; I spent five years on this film and only this film for the most part,” producer Jonas told LAist. “In the course of producing one film through all the story iterations and animation, people in live action could probably produce four films.” There’s one very special easter egg you might have missed What is the other greatest Pixar film of all time besides Inside Out? It’s Up, obviously. The filmmakers found a way to include a very special easter egg to honour the beloved 2009 movie. One eagle-eyed Redditor noticed that among the scenes depicted in Riley’s memory orbs were two moments from Up – one of Carl and Ellie’s wedding and their house. Naturally, this sparked plenty of fan theories about whether Inside Out exists in the Up universe or if (just to play with our emotions even more) Up could have all been a movie even in the Pixar universe. Inside Out was never actually aimed specifically at adults or kids It’s no secret that Inside Out resonated across generations, but its creators have insisted that it wasn’t targeted towards one age group more than the other. “We kind of made it for ourselves,” director Pete Docter told The Verge. “We’re not talking down to kids or up to adults; we’re just talking straight across to us.” Producer Jonas Rivera elaborated: “We brought in all the kids from our crew, and their neighbours and soccer team kids, and we ran it and sat in the back and watched everyone. “We were pretty pleased; they all got it pretty well. Not just the story, but how it all worked. I asked a bunch of questions – ‘What are their jobs?’ – and they beautifully told it back. Sometimes better than the parents.” Inside Out is currently available to stream for free on BBC iPlayer, as well as on Disney+.