But they are tricky, and they change.
Which is why Apu, the fictional Indian-immigrant character in "The Simpsons," has sparked a backlash against America's longest-running sitcom.
Now, I find Apu to be a funny character who has made America laugh for a long time. Yet, while America has changed, Apu has not.
Apu is voiced by Hank Azaria, a white actor who uses an Indian accent based on another white actor doing an Indian accent in a previous film (a caricature of a caricature). "The Problem with Apu," a documentary by Hari Kondabolu, shows why the character has been so offensive to many Indian-Americans and other South Asians for so many years.
South Asian performers make this clear in the documentary: Kal Penn says he "hates" Apu, while Aziz Ansari says he was taunted about Apu growing up. Similar moments of backlash have occurred regarding the constant portrayal of South Asians and Middle Easterners as terrorists.
Azaria this week told Stephen Colbert, "I wanted to bring laughter and joy with this character. The idea that it's brought pain and suffering — in any way — [or] that it's used to marginalize people, it is upsetting."
A recent episode of "The Simpsons" dealt with the issue by having its characters talk about "political correctness." But that misses the point.
Of course, the show has every right to continue portraying Apu as it has been over the past three decades. But in doing so, it runs the risk of making lazy, irrelevant comedy.
The fact is that "The Simpsons" is an iconic franchise. In reaching households around the world with its unique brand of comedy, the show represents who we are as Americans. The question is, does the show represent who America is today?
When it comes to the community Apu represents, America is more different than ever. Just over 20 years ago, there were more than 1.9 million South Asians living in the United States. The population grew 81%, the fastest growth of any major ethnic group, to reach more than 3.4 million South Asians living in the United States in 2010.
Today, Indian immigrants are younger, more educated than native-born Americans, and they work disproportionately in science, technology, engineering and math. When American students go to college, they study with Indians, who are the second-largest group of international students in the United States.
Some South Asian Americans run convenience stores, but others, like Sundar Pichai, run Google. Indeed, the contributions of South Asians to the United States, since Apu was created nearly three decades ago, fall across the labor market, helping create the most dynamic and innovative economy in the world.
Let's be clear: We can, and should, continue making fun of one another. We live in a complicated and changing society. Humor remains a critically important communication tool.
But we can do humor with more respect. As actor Kumail Nanjiani put it, "Norms evolve. Societies grow. We learn. We acknowledge mistakes as a society. Something that was acceptable in the past may not be acceptable now."
Good comedy challenges stereotypes by acknowledging stereotypes. Bad comedy perpetuates stereotypes by pretending they don't exist.
In our polarized America, where it is harder and more important to be funny than ever, writers and actors with a diversity of life experience lead to a sophistication and depth of comedy that is missing in Apu.
"The Simpsons," and the entertainment industry writ large, are better off creating shows that both challenge and represent America. This is only possible if the shows are run, written and acted by people who represent a diverse collection of gender, race and religion.
Because if there was ever a time we need to laugh at and with one another with respect, it is now.