What would you do if I told you there's a whole demographic group that can't be trusted to work because they're unreliable, bad with technology, slow learners, and most likely not a good "culture fit"? What if I said that group probably shouldn't even be incorporated into the rest of society – that they should live in their own, separate communities where the rest of us don't have to see or interact with them unless we choose to?

Would your hackles be raised? Would that language have you dialing up the ACLU?

It probably should. It's called stereotyping. (Heard of it?) And while many of us some of us have trained ourselves to notice how stereotypes work when it comes to things like ethnicity or gender, there are other categories where the practice goes painfully unnoticed — like age.

As it becomes increasingly inevitable that our next presidential election will be a contest between Joe Biden and Donald Trump, everyone from comedians to competitors to journalists to doctors to the candidates themselves has had something to say about how old these two men are, and (in some cases,) why that proves that they're unfit for office. Recently, those conversations have gotten to a fever pitch.

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That's a big problem. Tracey Gendron is a gerontologist and the author of the book Ageism Unmasked. She says that like many other giant identity categories, "age in and of itself does not tell you what somebody's experiences are, what somebody's values are, what somebody's health status is, what somebody's cognitive status is." But because many people are taught to fear or demean older people, Gendron says age becomes an easy proxy for other concerns, "like, what is your ideology? What are the actual issues at hand? What are your voting records? What are, you know, the actual things that should make me support a candidate?"

These conversations about age have consequences outside of our immediate political circumstances. As it turns out, fixating on someone's age can actually put them at higher risk for exhibiting negative behaviors associated with that age. It's called stereotype threat. For instance, when people are told that members of their age group are likely to struggle with things like memory and word recall, they perform worse on memory tests than people who are primed with information about the vast cognitive capabilities of people their age. Similar studies have been done with gender, race, and many other categories, and guess what? Being told you're going to be bad at something is a remarkably consistent self-fulfilling prophecy.

So, look: Next time you feel tempted to criticize someone, try to focus on the specifics. There are so many nuanced, individualized, intricate reasons to hate on someone — or at least, find them unqualified for office. Defaulting to age is just lazy. (Who are you, a millennial?)