Blog by Sumana Harihareswara, Changeset founder

09 May 2012, 9:34 a.m.

Common Sense

Hi, reader. I wrote this in 2012 and it's now more than five years old. So it may be very out of date; the world, and I, have changed a lot since I wrote it! I'm keeping this up for historical archive purposes, but the me of today may 100% disagree with what I said then. I rarely edit posts after publishing them, but if I do, I usually leave a note in italics to mark the edit and the reason. If this post is particularly offensive or breaches someone's privacy, please contact me.

When I was young, my family told me, over and over again, that I had no common sense. It still hurts me to think about this. When I didn't understand how to do something, or why, or I did some household task wrong or whatever, they told me that I didn't have common sense. (I have no memories of the mistakes or of any other correction and help, just the "no common sense" complaint; my memories are as jumbled and incomplete as anyone's.) They never told me how I could learn common sense. It was just this urgently necessary knowledge that everyone else had and I didn't, and it was connected to their belief - which I accepted - that I was inherently unable to get along by myself "in the real world."

In the nineties I saw a PBS series about computing that mentioned Cyc, the effort to just tell a computer all this stuff, and it stuck with me. I sympathized so much with that computer; in retrospect, I think I was envious of it, because someone was systematically trying to give it all the data it would need.

To this day I hate phrasings like "common sense" and "real world," because of their inherent assumptions and implicit exclusions, and I try to be generous with newbies in my communities who don't know our specific practices. See the "no feigning surprise" norm. Today's xkcd approaches it from an unimpeachably quantitative point of view, and I hope that helps prevent some of the qualitative hopelessness and despair I felt. Kids want to learn; don't belittle them for not knowing something already.


11 May 2012, 20:01 p.m.

I think that there are two (or more) things bundled into "common sense". One of these is a form of knowledge --- knowing the stuff that "everyone knows" --- but there's also the ability to extrapolate and infer connections.

For example, a person might know not to hang drapes so that they dangle near the oven burners because they have been told so, or they might know it because they have the extrapolative ability and attention to detail to picture the consequences.

I wouldn't expect young children to be good at either of those things, especially since the extrapolative-and-inferential thing is a prefrontal cortex function, and that part of the brain develops fairly late, still cooking into the mid-twenties.

13 May 2012, 15:42 p.m.

I love this post. Especially this: "I sympathized so much with that computer; in retrospect, I think I was envious of it, because someone was systematically trying to give it all the data it would need."

14 May 2012, 2:40 a.m.

It used to drive me crazy on NextGen that instead of explaining to Data why what he'd said was awkward or funny, they just had everyone look at him as if he had two heads. It's not like he wasn't capable of learning, but nobody would BOTHER.

14 May 2012, 11:29 a.m.

In your particular instance, I think the practical translation of "common sense" = "telepathy." "What? You don't just intuitively know what I want you to do and how I think you should do it? But I've been THINKING it at you, and you WEREN'T PAYING ATTENTION." Yeah.

My brother's particularly snippy and supercilious version: "Jacque, your ignorance is showing."

Dave Harmon
15 May 2012, 17:35 p.m.

Oh man, that's all kinds of wrong there...

1) Children don't have common sense, that's why they need adults to keep them out of trouble and teach them about the world.

2) Insulting a kid instead of teaching them doesn't help them learn -- and the "essentialist" aspect is particularly hurtful. It's basically saying they're broken -- not just "you did something wrong", but "you are defective, and that's why...".

I got a fair bit of that growing up as an undiagnosed spectrum kid... aggravated by the fact that I was (and am) also hard of hearing, which wasn't diagnosed until I was in 4th grade (age 9). Cue lots of "well, I told you" (without actually checking to see if I'd heard them).