Why isn't this accepted answer appearing above other answers?

Question

While browsing What is Hermione Granger's ethnicity?, I was surprised to see the top answer by votes wasn't accepted, when the icon in the questions list was green, indicating it had an accepted answer. I've since checked other questions and they all appear to behave this way.

I thought "maybe the OP unaccepted at the exact moment I was looking", but when I scrolled further down, I saw the accepted answer several answers down. At this point I thought it might be some weird sorting choice, but I was unable to get the accepted answer to appear at the top of the page, despite choosing all three answer-sorting options.

Isn't the accepted answer supposed to appear at the top of the answers list regardless of sorting method? It appears to work that way on other Stack Exchange sites and is hinted at in the Tour page animations here, as well.

Answer 1

The accepted answer to this question was a self-acceptance, and self-accepted answers aren't sorted to the top.

This behavior is documented in a Stack Overflow blog post by Jeff Atwood (emphasis added):

Now, there are some special rules around owner-accepted answers, to prevent gaming:

• Wait 48 hours. You must wait 2 days from the time you originally asked your question before you can accept your own answer. This gives other users a chance to answer the question in good faith, and earn the accepted answer.

• No change in sort order. Normally, accepted answers are "docked" under the question. This is not true for owner accepted answers; they stay in standard sort order like any other answer.

• No reputation is earned. Normally, accepted answers confer +15 rep to the answerer and +2 to the owner. Owner accepted answers do not earn rep (or badges) for anyone.

Similar questions about this behavior have been asked on the main Meta. For example, this question asks about it and was tagged "status by design" by the admins.