I often find explanations-for-downvotes useful. If they're coming from the SAME person, I'm likely to still disagree with them, and thus downvote them again (this is rarely the case with third-party explanations). Days or weeks later I'll finally drop the tribal posturing, actually THINK about it, and sometimes update my stance. I'm MUCH more likely to update if I've engaged someone thoroughly (which will result in a thread of comments by them, all of them downvoted by me)

... I should probably stop negatively reinforcing this with downvotes >.<