Nielsen reveals that the Pixar animators had shown the film to the girls, asking them some questions to ensure that the plots were truthful for young audiences who are also experiencing changing moments during adolescence.

The girls wrote notes to share their thoughts about the characters, providing insights into how they felt about Riley's relationship with her group of friends and whether they resonated with the plots.

"Kelsey (the director) and I were in middle school but we've never been teenage girls. This group of girls was incredibly helpful to us," says Nielsen, laughing loudly.

For the Pixar animators, crafting the anthropomorphic embodiments of "emotions" posed one of the biggest challenges.

"We can ensure that a leaf resembles a leaf. However, delving into the complexities of the human mind is a whole other realm. My initial step was to bring back Dacher Keltner, one of the key experts from the original film," Mann reveals.

In addition to incorporating expert perspectives from Keltner, a psychology professor at the University of California, Berkeley, and the director of the Greater Good Science Center in the United States, Mann delved into the works of clinical psychologist Lisa Damour.

Damour is renowned for her New York Times bestseller, The Emotional Lives of Teenagers: Raising Connected, Capable, and Compassionate Adolescents.

"We are not only creating an entertaining film but also striving for scientific accuracy," the director says.

As children transition into adolescence, their emotions resemble a roller-coaster ride, easily shifting from one extreme to another.

Within the film, Pixar's animators designed a team of emotion "architects" who abruptly invade the "headquarters" of Riley's brain, executing a forceful and somewhat rugged demolition and reconstruction, introducing new emotions in an almost unpredictable manner.

Mann elaborates further on how the animators visualized the psychological transformations.

"I got excited about an image of a wrecking ball smashing through the headquarters and then having to go through demolition. It's really funny, but it's true to the science. This is a visual metaphor of what is actually happening to teenagers and what goes through in their minds," he explains.

Nielsen, who also served as an associate producer for the first Inside Out film, hopes that the sequel will inspire families to engage in meaningful conversations, particularly about challenging emotions like anxiety, which are relevant to both adults and teenagers.