Have you ever played dumb in any specific social situation so that it might give you an advantage?
More than once - when you realise the person/people you are interacting with will not have a clue what you’re talking about, and it becomes necessary to dumb down the choice and depth of conversation topics in order to save embarrassment to all concerned.
In my case I can recall several occasions when at a pub quiz or playing Trivial Pursuit when I would be too embarrassed to admit I knew the answers to certain questions and kept my mouth shut.
I would like to take this opportunity to apologise to my teammates. 
Not for any length of time or to gain any advantage but if someone is telling me stuff I already know or stuff that is just plain BS I don’t always act as though I know or that it is BS. But it’s just like dealing with kids. When they excitedly tell you something you know it’s just rude to spoil their pleasure in telling you.
Most notably, at those times in my life when one or another female was hinting at taking an acquaintanceship to a different level and I wasn’t interested.
It’s much easier for all concerned to play “clueless guy”, act like you don’t understand the hints, and nobody’s feelings have to be hurt.
If she later wants to tell her friends I’m really stupid and clueless, that’s OK by me. It’s still better than enduring a messy rejection scene.
What do you mean?
I’m female. I will never, ever be stunningly beautiful but I have cuteness coming out of my pores. I have a baby face, I’m 30 and still get carded. So hell yeah - not so much dumb but lost and clueless. large eyes “Please, sir, could you help me get this thing down from the top shelf? There’s no way I could manage by myself.” I got out of lots of things in school, too…I was always the good kid, so when I was the bad kid I could be innocent. “Skip class? I’m sorry, I wouldn’t even know how to do it and get away with it!”
I have no problem doing this. Other people use their beauty, I use what I’ve got. I should point out that I never use it for something I can actually do, only for things I can’t do.
I can’t pretend to be stupid. I mean, I honestly can’t. I’m a horrible actor, and it shows.
That being said, when I’m with certain branches not-too-bright of my husband’s family, I get really, really quiet. Because being smart and/or witty around them isn’t exactly going to win friends and influence people.
Who’s pretending? 
I will, on occasion feign ignorance when I’m unsure of all the facts because I feel better having no idea about a subject than thinking I know it well and being proven wrong in discussion. Plus, feigning ignorance can net you a new explanation of the subject that will hopefully fill in the gaps in your own knowledge or give you a reason to voice whatever questions you had. It’s a very useful tool for gathering information without risking any ego.
Heh, I manufacture semiconductors for a living.
99.99% of the time I have to dumb myself down and tell people I make computer chips for a living because they don’t know what the hell a semiconductor is.
I got tired of Chinese people trying to sell me crap in the Forbidden Palace so I tried pretending that I only spoke German. Unfortunately the guy just switched to trying to sell me crap in German. Oops.
Many times. I’m in the marketing business, so on occasion I like to see how those in the know about a certain subject sell things to people who are not in the know. I’ll pretend to be stupid to see how people describe things I’m already familiar with, where they cut corners and oversimplify, when they tell out-and-out lies, etc.
One of my favorite things to do in a meeting is respond to “What do you know about [topic X]?” with “Not a damned thing. Can you cover the basics for me?” Depending on what I hear back from the person across the table, I can make judgments about how trustworthy and informed they are.
I quite often find folks more willing to help out and instruct someone they think less intelligent than them, than providing specific service or information in response to an intelligent request. When dealing with retail personnel, my motto is generally “Act stupid, they’ll certainly believe you capable of it.”
Often people will cut more slack to the pleasant stupid person who makes them feel smart, than the well-informed person acting within his rights. My goal is not to impress the salesperson with my intelligence, but to get the service/product I wish at the best price.
Hit submit to soon:
Another situation is when you are doing something you suspect (or damn well know) might not be quite kosher. Say you move up to better seats midway through a play or game. Heck - pushed to an extreme you might even crash a reception or something.
“Gee, I didn’t know. No one told me. I’m really sorry.”
I’ve done this to get out of tickets.
Never tickets where I was doing something incredibly stupid - I just generally bow down and take it, and the officer let me off with a warning, usually (I’ve only done something incredibly stupid in a car twice anyway, back in my stupid youth days). But when the officer tries to bust me for not stopping (When the stop sign had been removed from the stick and there was no stop line…normally I come to complete stops) or speeding (I make it a habit to only go 5 over at most unless I’m on a long, somewhat empty stretch of highway), I’ll bat my eyelashes and act like I have no clue what’s going on, and they usually let me off with a kind warning.
Social situations, though? Never. I make it a habit to only hang out with intelligent people anyway, and any other time I just don’t care.
~Tasha
Many times.
The most outrageous thing I’ve done was to pretend I was new when I screwed up at work, and had people feeling bad for me.
Not proud of it, but it worked.
I do the same thing, especially with older men. Yeah, part of me is offended by the patronizing “little lady” tone that some of them take, but getting upset about it would do nothing but cause hard feelings.
I used to play dumb with one of our secretaries just to aggrivate her. I forget exactly how it started. I think I was trying to use a fax machine which I had never used before and wasn’t sure how to operate it, and she made some snide comment about how us supposedly “smart” engineers couldn’t figure anything out. So I ran with it. I made her explain every excruciating detail long after I had figured out how to operate the machine, and continued to do act dumb for anything else I could. It took her a while to figure out that I was acting dumb intentionally. Of course, just because she figured it out didn’t mean I had to stop. It became sort of a contest. I would see how long I could get her going before she realized I was yanking her chain.
I feel your pain.
I design hardware and software for use in manufacturing plants. I’ve been doing it for almost 20 years. My mom still doesn’t have a clue about exactly what it is I do. About a year ago I gave her a handful of non-working prototype boards that I keep around for show and tell sort of things and said “here, I designed these”. I’ve given up on explaining the software side of things to her.
Socially, not often. If I am after an advantage socially I find that it most often backfires unless it’s a very limited situation.
Professionally, oh yeah. All the time. Ruthlessly. My great aunt Lilly from the old country told me that people who could be manipulated by a smart woman acting stupid probably should be.
Though after I moved to Holland I did find that people sometimes think I am stupid either because of my incomplete grasp of the language or because something falls into the Cultural Gap (this is a great yawning abyss formed because there are things which all right thinking people agree are self evident which you don’t know because all the right thinking people where you grew up agreed that other things were, um, self evident). This prickles my pride on occasion, but mostly I just get over it. My ego is as big as a barn but I harbor no fantasies about bucking the dominant culture. Not any more anyway.
All of the time in my job. If I get someone in here who ‘thinks’ they are really smart, I will play into that. I consider myself a numbers guy, I can do computations in my head that take most people ten minutes on a calculator. But if someone comes in and tells me “I am accountant, you can’t pull a fast one on me”, I will watch him use the calculator, stumble a few times, come up with an incorrect number, and congratulate him on how smart he is. When the wife is with him (or husband with her), I will tell them, “Wow, that is good”. Man’s ego is built up, he is a complete idiot, and I just made a lot of money.
Helps to play ‘I’m not that bright’ sometimes.