Sheldon Cooper Isn’t the Main Character In The Big Bang Theory, Here’s Why

By Robert Scucci | Updated

Fans of The Big Bang Theory are right to assume that Sheldon Cooper (Jim Parsons) is the main character of the series, but I actually think it’s Penny (Kaley Cuoco) for a number of reasons. It’s an undeniable fact that Sheldon, Leonard (Johnny Galecki), Howard (Simon Helberg), and Raj (Kunal Nayyar) are the primary protagonists in the long-running CBS nerd-fest, but Penny has the most interesting character arc throughout the series’ 12-season run.

While it’s easy to simply write Penny off as Leonard’s love interest in The Big Bang Theory, her evolution leads to the most satisfying conclusion, and out of all the characters, she sees the most growth.

Penny Starts Out As The Outcast

The Big Bang Theory Penny's first appearance

The Big Bang Theory begins with Howard and Leonard walking up the stairs of their Pasadena apartment building (because their elevator is perpetually broken). They have their awkward first run-in with Penny, an attractive blonde who Leonard immediately falls in love with. At the series’ outset, Penny was supposed to be the bubbly and not-so-bright love interest, and she looks and acts the part.

Penny’s perceived lack of intelligence makes her the butt of many jokes because she’s an aspiring actress working as a waitress at The Cheesecake Factory. She’s clearly an outsider because Sheldon is a senior theoretical physicist, Leonard is an experimental physicist, Raj is an astrophysicist, and Howard is an engineer-turned-astronaut in The Big Bang Theory. But despite the main gang’s big-brain endeavors, they’re inherently stupid when it comes to reading social cues and partaking in regular every-day activities.

Penny Isn’t Stupid

The Big Bang Theory Penny

A recurring theme in The Big Bang Theory is the comparison between Penny, who’s an emotionally intelligent young woman, and a bunch of science guys who have a collective IQ of 675. Penny, who is of slightly above-average intelligence and boasting an IQ of 110, isn’t stupid by any stretch of the imagination, but by comparison, she falls into below-average territory when hanging out at Sheldon and Leonard’s apartment with the rest of the gang.

For context, the average IQ falls between 85 and 115, so she’s on the higher end of the “average” spectrum of intelligence.

The reason I have to consult these numbers is because Penny more often than not acts as the voice of reason, as her logic is grounded in reality instead of wildly speculative science propped up by theories that haven’t necessarily been proven.

Penny Is The Most Well-Rounded Character

The Big Bang Theory Leonard and Penny

While Sheldon, Leonard, Raj, and Howard can play a mean game of Dungeons & Dragons, they’re often preoccupied with their work, which leaves them with little to no time to form meaningful relationships outside of their friend group in The Big Bang Theory. Conversely, Penny has dating experience, and by Sheldon’s estimation has dated 193 men in her lifetime before ultimately committing to Leonard in the later seasons.

To put it simply, Penny’s presence in The Big Bang Theory pushes each principal character out of their shells, and makes them more rounded human beings. She’s quick to offer relationship advice, be the shoulder to cry on, and offer a female perspective that the guys wouldn’t be able to consider on their own as they form love interests of their own throughout the series.

From Waitress To Industry Woman

The Big Bang Theory Penny Job interview

Penny’s career trajectory in The Big Bang Theory is also worth a look because she evolves the most out of everybody. Starting out as a B-Movie actress whose claim to fame was her lead role in a low-budget movie called Serial Apeist, her acting career doesn’t ever take off. Her dreams are shattered when she finally lands the gig of a lifetime as an extra in an episode of NCIS, but her scene gets left on the cutting-room floor, leaving her embarrassed and devastated.

In season 8, Penny decides to take Bernadette’s (Melissa Rauch) advice and takes a job as a pharmaceutical sales rep, and she proves to be a natural who quickly climbs the rankings throughout the rest of the series’ run. This may not seem like a big deal at face-value, but Penny takes a chance and completely pivots to a career that couldn’t be further from what her initial aspirations were at the beginning of the series. The rest of the gang has been singularly obsessed with their work, and more or less do the same thing for 12 seasons.

Penny Puts Sheldon In His Place

The Big Bang Theory Penny and Sheldon

Without Penny, The Big Bang Theory would be a show about four lonely nerds who never leave their apartment (aside from their frequent trips to the comic book store). She may be the outsider of the group on an intellectual level, but I’d argue she’s the most resourceful because she lives in the real, non-theoretical world. But most importantly, she’s the only person in the series who regularly challenges Sheldon, making her a hero of the highest order in my eyes.