A standard sitcom family usually has one or more of the following: the reasonable mom, the obnoxious little brother/sister, the "misunderstood" teen girl, and the stupid loser dad. Of course, to round out the nuclear sitcom family, there's one more element needed to balance out the 2.4 kids...
...the Dumbass Teenage Son.
Like the name suggests, the character is a male, a teenager, and incredibly stupid. Growing up and hitting puberty appears to have caused him to sacrifice some IQ points for height and hair. Often looked at with disdain by the rest of the family who view him as an annoyance at the worst of times, the Dumbass Teenage Son is often times easily tricked or manipulated by his other family members, even those younger than him. He has no aspirations of getting an education or a "real job", usually thinking about becoming a rock star despite lacking in musical talent. Sometimes, this character tends to pepper his sentences with Totally Radical phrases like "Dude!" or "Awesome!".
Dumbass Teenage Sons are common in sitcoms, but can be found in other genres as well. Sometimes they are shown to be Book Dumb or knowledgeable about certain things others don't know, but not all the time. Other times, they're average or slightly above academically but naive at first, and then get Flanderized into a box 'o rocks. They are rarely if ever the Main Character or get focused on unless it's being viewed with contempt by the rest of the family. May overlap with Dumb Jock if said teenager is portrayed as dimwitted but athletically fit. If he grows up and doesn't grow out of it, he's likely to become a Basement-Dweller.
- Downplayed with Peter Fox of Foxtrot. While he does play his electric guitar at wall-blasting volumes, he's otherwise mostly intelligent, his life revolving mostly around food and the fact that he can't seem to grow hair, gain weight or get muscles. A bad grade on a physics test was brought about by over-doodling on a diagram rather than a lack of brains.
- Jeremy from Zits comes off this way due to his lazy, selfish, slobbish nature, he can be brilliant if he actually applies himself.
- In Artemis Fowl: The Opal Deception, the title character plays this stereotype to a tee when out to steal a rare painting. He poses as the dim-witted, smart-mouthed, video game obsessed son of his bodyguard, Butler, as a successful distraction to the fact that's really a Teen Genius who's about to pull off the theft of a unique painting that is highly celebrated in the criminal underworld.
- Eric Matthews from Boy Meets World, though like Brad he was a bit smarter than the rest of the examples here before becoming Flanderized.
- All over the place in the Disney Channel Live-Action Universe:
- Cameron's probably the third dumbest person in A.N.T. Farm, behind his Bumbling Dad & Paisley The Ditz.
- PJ in Good Luck Charlie is a Genius Ditz. A good example would be his boss putting him on the case to find out whose been stealing chicken from the restaurant. It was the boss himself, and he put PJ on the case because he figured he was too stupid to work it out.
- Jackson in Hannah Montana comes off as this frequently, though he's more Book Dumb than anything.
- Zack from The Suite Life of Zack and Cody was a Bratty Half-Pint as well but got dumber as he got older. Averted with his twin brother, Cody, who became an Insufferable Genius.
- Like The Above In Wizards of Waverly Place Justin is always studying and top of the class in every Subject, Max on the other hand falls into this category. The beginning of the show had him as more of a Cloud Cuckoo Lander than a ditz, though he was Flanderized into being very ditzy.
- The Disney tradition continues with Logan on I Didn't Do It
- There's also Ernie from K.C. Undercover, though he's a slight subversion being a Genius Ditz.
- Drake from Drake & Josh is like this, but at times is shown to be Brilliant, but Lazy. He devises a plan that would enable him and Josh to ride a Roller Coaster and be able to get back in time to watch over their Grandfather before their parents got back. Josh is stunned he's failing classes after hearing that.
- In The George Lopez Show, Max is depicted as being this, though he is later diagnosed with dyslexia. He also wasn't a teenager until the end of the show.
- Although he's smarter than most of those listed here. Brad from Home Improvement had his moments during the shows run.
- Reese from Malcolm in the Middle. To quote his own mother: "some people have book smarts, some people have street smarts, you have neither." To a lesser extent, Francis, who is sent to military school before the start of the series, though he's more a troublemaker than an idiot.
- Axl from The Middle. He's both the oldest and the most immature of the Heck kids.
- Though Axl tends to falls heavily on the lazy side of the Brilliant, but Lazy scale. When challenged by his parents, Axl actually managed to maintain a 3.0 GPA in his first year of college, and an episode where he's paired with his sister for a class project shows him engineering a lot of events by using his social status and calling in favors to fix a mistake with it.
- Junior from My Wife and Kids, Flanderized to where even his little sister had to help him with his homework. Little sister is about ten years younger than him. He even once forgot how to spell his own name.
- Averted with JJ from Good Times. Even though his "Dynomite" line tends to annoy James, and his sister, he is beloved by the family, and sometimes the line makes Florida laugh.
- That '70s Show: Eric is this in the eyes of his father Red, and while he's nowhere near as dumb as Kelso, neither is he a paragon of sensibleness. Then again, everyone's a dumbass in Red's eyes.
- Jake from Two and a Half Men was originally a Bratty Half-Pint, but as the show went on he got older and...dumber.
- Flashbacks in Titus show the title character was this as a teenager. In every flashback he's a stoned, drooling idiot reeled in by his tough, badass father.
- Theo Huxtable from The Cosby Show starts off like this, with the first episode in particular demonstrating a lack of intelligence when it comes to school. Later on in the show's run, he's eventually diagnosed with dyslexia, and starts working to overcome it. By the end of the series, he's become a teacher.
- Eddie Winslow from Family Matters starts as this but he grows out of it, though he occasionally has his moments even in later seasons. He's pretty much only Book Dumb by season 2, especially after his best friend Waldo is introduced and becomes the show's resident idiot.
- The Fresh Prince of Bel-Air: Carlton Banks is not dumb (he gets straight A's in school) but is still childish and naive, usually acting as a foil for Will and even his father Phil at times, who tells him to "Shut up" every now and then.
- JT from Step by Step is portrayed as an academically challenged slacker. Like Theo, he later finds out he has dyslexia.
- From The Sopranos, we have Tony Soprano's son, Anthony Junior (AJ), who is a lazy and spoiled kid without any real drive or ambitions in life. He frequently performed poorly in school, until eventually dropping out of college.
- Jimmy, Michael de Santa's 20-year-old son in Grand Theft Auto V, isn't a teenager anymore, but otherwise fits every other beat of this trope. He still lives with his parents, leeching off of them and doing nothing but sitting around all day playing video games and speaking in hip-hop slang.
- Deconstructed with Inigo in Fire Emblem Awakening. During their B support his father accuses him of being a carefree fool who only cares about chasing skirts after Inigo is wounded in battle, causing Inigo to promptly explode that no, that is not the case:
You may think me a dandy and a fool, but a lot of people depend on me in the future. Every day, I was out there fighting Risen and risking my life. With everyone looking to me to be strong, I had no choice. I HAD to be invincible. I couldn't complain or show any weakness. Not with everyone else struggling in that damn war-torn wasteland... Even with you and Mother gone, I had to pretend I was fine. That I wasn't hurting. I had to fight every day of my sorry life and wear a smile while I did it!
- Even more so: If Chrom is Inigo's father, Chrom's Future Past talk with the Inigo of the other world reveals that this version of Chrom!Inigo (and most likely the one you recruit) additionally has massive issues because he views himself as inferior as his older sister Lucina, and believes himself to be unworthy of holding up Chrom's legacy. But Chrom will tell him otherwise.
- Destiny:You know the universe in general has problems with idiot teenagers when the local alien God of Evil has one. Crota, Son of Oryx, is good at killing...and not much else, he also being something of a reckless numbskull who is partially responsible for accidentally releasing the Vex into the universe and letting them colonize his father's own pet universe for over a century to show off to his sisters. He was goaded into it, but come on.
- The Cleveland Show has Raymond, Tim the Bear's stoner son.
- Chris Griffin of Family Guy is one, but to due to lack of focus the viewers don't really see him acting dumb.
- Joseph Gribble, Dale's son from King of the Hill. This can be partially attributed to Dale, a massive Conspiracy Theorist and general nutbar, being his primary parent. And unlike most examples, he loves his son and often works with him on various crazy projects.
- Junyer Bear from the Looney Tunes Three Bears shorts. He appears to be a teenager, and yet he still wears diapers.
- Reggie DeBoar in Pig City. He's not too bright, and plays guitar in a rock band that he formed with his friends.
- The Simpsons: Bart Simpson is often depicted as this during episodes that take place in the future when he and Lisa are growing up. Homer was one as well growing up.
- Kevin from F is for Family is a pretty standard example, being a Book Dumb stoner with dreams of being a rock star. Unlike many examples though, he does get his own story-arcs and is shown to have a lot of emotional depth where his intellect lacks.