User level and editing comments

I’ve searched on this topic a number of different ways and have come up empty. I’d like to allow users to edit their own comments–only their own comments–to correct errors. I’ve researched the user levels in the codex, and from what I read there I’d have to bump users up to level four before they could do that, is that correct?

I am wary about doing that because it also gives them the power to add/delete/edit categories and moderate comments. Is there another way to allow what I want users to be able to do, without giving them any more power than necessary?