Q. How do you get a retard to commit suicide?

A. Put a knife in his hand and ask, "Who's special?"

I've known that joke for as long as I can remember. When you grow up with a mentally retarded sister, you have the retard-joke canon forced on you pretty quickly. "What's better than winning the Special Olympics? Not being a retard." That's another chestnut.

As a kid I used to hear the suicide joke all the time, and it never failed to upset me. As an adult I don't hear it much, probably because most adults realize that if you tell it in mixed company, there's a reasonable chance someone will call you an asshole. Which means the only safe place for an asshole to repeat it is the Internet. Where lots of them do.

Funny thing is, I've recently started thinking about that joke in a way I never have before. I now like to imagine it as the sort of thing two self-aware retarded people might share with each other as a biting critique of the overly sentimental garbage they're buried in every day. I mean, if I'd spent my entire life hearing "normal people" I barely knew go on and on about how my struggles had inspired those around me, about how God had specifically chosen my parents to raise me because they were saints, about how the patience my disability required had taught others the true nature of love—I'd probably feel like plunging a knife into my head, too.

Allow me to address the elephant in the room: yes, I use the R word. I've never used it the way Rahm Emanuel used it, when he called left-leaning Democrats "fucking retarded" during negotiations over the health-care bill. I've never used it the way Rush Limbaugh used it, in response to the Emanuel controversy, when he criticized our "politically correct society" for "acting like some giant insult's taken place by calling a bunch of people who are retards 'retards.'" I've never even used it the way Stephen Colbert used it, calling Sarah Palin a "fucking retard" after she demanded Emanuel's dismissal for his apparent insensitivity, then immediately turned around and defended Limbaugh's remark as "satire." To me, the R word has only ever had one acceptable application—and even that one's slippery.

In 1970, when my sister, Jenny, was born, retarded was the catch-all term for anyone with a mental disability. It was the term every doctor and specialist used when her condition was first diagnosed. It's the term every educator used while she was in the public school system. It's the term my family has always used when we talk about her, and out of habit and convenience we probably always will.

Advocacy groups like the Association for Retarded Citizens (which once counted my mom as a chapter president, my sister as a program participant, and me as a volunteer) started distancing themselves from the word in the early 90s. They did so for a number of reasons: it had come into favor at a time when the mentally challenged were routinely institutionalized; it had been popularly adopted as slang for "stupid"; and, most important, it was far too reductive. The ARC served people living with a wide range of disabilities—Down syndrome, autism, cerebral palsy—whose needs and capabilities were never exactly alike. To group them all together as "retarded" was inaccurate at best and insulting at worst. So the ARC changed its name to the Arc. Other groups followed suit. New terms—developmentally disabled, intellectually challenged—came to the fore. The R word became a relic of a less-enlightened past.

But when it comes to my sister, I still use it. Here's why:

When people first get to know me, sooner or later they run through the standard battery of questions about where I'm from, what my family's like, whether I have any siblings. Easy stuff like that. But when I tell them I have an older sister, it gets tricky. Because the next question, invariably, is what does she do?

I suppose I could be coy, just say she lives at home with my dad and let people think what they will. But that makes it sound like I'm hiding something, or ashamed. So instead I come out with it. I know in some circles it might be considered more sensitive if I said she's developmentally disabled, or mentally challenged, or that she has special needs. But then there'd be more questions. Does she have Down syndrome? Is she autistic? What exactly is wrong with her?

I could get technical and say she's microcephalic, which basically means her brain stopped developing at a certain point. But if I told you that right off the bat, would you have any idea what I was talking about?

Or I could go the other way and just say, literally, what she does: Well, she gets up in the morning, gets dressed with assistance, eats a breakfast someone has prepared for her, then takes half her daily allotment of epilepsy pills (usually around a dozen, and yet she still has seizures). After that she goes to a day program where she paints pottery with watercolors and asks everyone in sight what time they woke up and whether or not they took a shower, because those are her two favorite topics of conversation. Then she comes home, takes a nap, eats a dinner someone has prepared for her, watches a Barney the dinosaur video, listens to the same Whitney Houston mix tape she's been listening to since the mid-80s, takes the rest of her pills, and goes to bed. The next day she gets up and repeats the same routine all over again.

It isn't a bad life, but as is the case with most of us, it isn't a terribly remarkable one, either.

So in the end I just say she's severely retarded, and whoever's asking more or less gets the picture.