Turn off auto-spell in iMessage (Mavericks)

Mavericks's aggressive auto-correct could become annoying especially if you use iMessage. Here's how to turn it off for iMessage. After that, I'll show how to turn it off in general using System Preferences.

To turn off auto correct in iMessage: 

1. Open iMessage and click on any existing chat thread.
2. On the iMessage menu, click Edit > Spelling and Grammar.
3. Uncheck "Check Spelling While Typing".
4. Uncheck "Correct Spelling Automatically".

Somehow, Apple decided not to make auto spelling universally controlled in System Preferences. But you may have to turn that off, too. Here's how.

To turn off auto correct in System Preferences: 

1. Click the Apple icon and select System Preferences.
2. Click Language and Region.
3. Click the Keyboard Preferences button.
4. Click the Text tab.
5. Uncheck the "Correct spelling automatically" box.