Is Address Book merging data between entries and then contaminating Contacts in OS?

I'm seeing what seems to me like AddressBook confusion, with a nickname previously entered for one contact appearing as the nickname for a contact I had linked to it. When I add contacts to an iOS7 Mail, I add two linked people in the To field, but in the Cc to myself I see one of the names listed twice. When I forward the message to the one not listed, I see in the attached copy that he WAS listed, so it's only the display of the Cc copy that was wrong.

One contact in Mavericks AddressBook was so jumbled with another linked contact that I deleted it and entered all the data into a new entry. Later, when I opened the brand-new entry, it was as jumbled as before, as if I never deleted it.

Please note that the interconnectivity and background syncing has propagated these confusions through an iPhone 3GS, iPhone 5, iPad 2, and iMac (mid 2012).

Could I avoid this by removing the links between contacts (I think this is a new feature)? This would be very tedious, so I'm hoping for an easy fix.