[laurenbee]

By asking/telling someone to smile, one is basically saying, "You should look more pleasant for my benefit." I can't see asking someone to smile being appropriate in a workplace setting unless the person is in a customer-facing role and it affects job performance. The sexist part is that it seems to happen far more often to women than to men.

[ManlyBread]

Or maybe you just want to actually cheer up that person? Not everyone follows the sociopathic line of thinking you presented.

[wetmore]

How does telling someone to smile cheer them up? Besides, you can be cheerful but not smile.

[rickyc091]

I mean kids will typically end up laughing if you tell them to smile.

[rpdillon]

> bascially saying "You should look more pleasant for my benefit."

Perhaps not.

http://www.scientificamerican.com/article/smile-it-could-mak...

Tone of voice and mannerisms tell a much fuller story, though.

[mthoms]

Exactly this. Context is everything. Human communication is very nuanced.

[mthoms]

That's quite an assumption (that it has anything to do with physical appearance).

It's equally possible that it was intended as a shorthand for "cheer up, it's not that bad" or "try to keep your chin up". Both of which actually indicate that the speaker cares about their colleague.

Sure, I can see contexts where it would be inappropriate to say but that doesn't make it always inappropriate to say.