I touched on the singular they in the past, and I recommend you follow the link if you don’t know what the singular they is. Today I ran into a usage of it that jumped out at me a little, so I thought I’d share.
First, look at the conversation in the third panel of Scott Meyer’s Basic Instructions:
Since we’re talking about spouses here, the issue of “his” or “hers” being the right word is a little stronger than it would be in a lot of other contexts. On one hand, in this context he’s talking about his wife. And on the other hand, he wants to make his statement tactfully general. And on the third hand, Scott is somewhat constrained for space, so “their” fits better than “his or her.”
Now look at panel three’s heading. Same problems. Scott doesn’t have much room, and he doesn’t know whether your spouse is male of female. So even though the topic is spouses, which is reasonably gender related, which would make “his or her” appropriate, he chose “their.”
Writing can get tricky sometimes, eh?