The Addamses really did love Debbie.When Debbie strapped the family into electric chairs, and asked them whether any of them really loved her, Gomez calls for a show of hands, and all the other family members try to raise their hands. Thirty seconds into Debbie's (unbelievably selfish) Start of Darkness monologue, Grandmama seems totally on her side, and the entire family seems to sympathize with the multiple murders she's committed for sheer greed. Debbie had a hint of the family in her, but was just too selfish to see that she'd found a home and family that could love her for what she really was.
The Addamses are like that due to the ability to see ghostsIn the musical, it is notable that only the Addamses seem to notice all the undead ancestors walking around; the guests don't seem to be able to see or hear them. Logically, this means that the ability to perceive ghosts is unique to the Addamses. Presumably, prolonged exposure to the spirits of the dead from a very early age is the cause of their unique perspective on mortality and how to live one's life, as well as their odd design aesthetic sensibilities and hobbies.
Fester isn't the real Fester.He really was Gordon Craven, and really was trying to get the Addams' money, but their insanity grew on him and he ended up brainwashing himself.
The Addams Family are a state of mind! Or a mental disorder.Literally, the Addams family (Gomez, Morticia, Fester, Granny, Pugsley and Wednesday) are what you become when you visit the Addams house and, instead of running away, start to empathise with them too much. It explains the slightly different versions of the family in the different adaptations. Luckily, along with a propensity towards enjoying torture and violence, you also become imbued with a supernatural toughness and regeneration that will even bring you back from the dead and will somehow 'inherit' (from a family member that never existed till then) a large and spooky manor complete with a bottomless fortune, a huge butler, a friendly severed hand and any number of family members. Of course only one such family exists in any given world, which is why all the different adaptations are all canon.
The Addams Family acts that way because they are all Nigh InvulnerableEveryone in the family seems really hard to kill. Wednesday and Pugsley try to kill each other constantly and always live, Pubert can survive long drops and catch guillotine blades, and all the family members in the graveyard seemed to require rather brutal means of putting them down. If you and everyone in your family were that hard to kill, it's likely that you'd develop a rather blase attitude toward violence and mayhem. They don't quite realize that others are more vulnerable, so they rarely hold back when dealing with other people.
The Addams Family is in the same universe as Harry PotterThe Addams Family and their relations are magic using Wizards the same as those in the Harry Potter universe. While the Wizards of England and Europe have formed themselves into highly class-stratified societies with guilds and academies, the Wizards of North America and the United States have gone to a more independent model that we see in The Addams Family. This fits with the more casual nuclear family attitude that one sees in mainstream US culture and the fierce family loyalty that the Addams have. The Wizards of the New World would have also been highly affected by the frontier culture of the early United States: self-sufficiency, "pulling yourself up by your bootstraps". They eschew titles, nobility and cultural ranking systems, are much more casual with acquaintances and are more egalitarian and dealing with "muggles" day to day.
In Addams Family Values, Wednesday and Pugsley really did just want to play with the baby.It's been demonstrated that their definition of "play" involves axes and electric chairs. There's no reason for them to assume that their brother would be any less Nigh Invulnerable than the rest of the family. So, while there may be some legitimate sibling rivalry, the attempted guillotining and repeated drops from high places are just normal Addams playtime.
The Addamses aren't Nigh Invulnerable, they merely go easier on each other than the dialogue implies.Pretty much all the graphic violence is hidden through discretion shots. The closest we see to any real harm coming to an Addams is Pugsley being electrocuted, and even then it's off-screen and we don't know just how much electricity was running through him. They may have increased tolerance for pain and damage as a Charles Atlas Superpower, but I don't think they're literally unkillable.
The Addamses are mostly Nigh Invulnerable to each otherRelated to the above. It's possible that Addamses are extremely resilient to damage inflicted by each other and themselves, and possibly by things they own, but can be harmed by outsiders. How this works would be subject to an entirely separate WMG, but it would be a handy explanation for both their casual "cruelty" to one another, but are worried by violence done to themselves by non-family members (And would mean that Debbie's best hope for killing Fester would have been before she married him).
Cousin Itt is an Oompa LoompaIn the 00s Charlie and the Chocolate Factory film, Wonka says that he has invented a sweet that restores your hair. He then shows us an Oompa Loompa who took the sweet, but the effect was too strong and the poor little guy is now completely covered in hair. Cousin Itt was one of the Oompa Loompas who was tested on one of the sweets and left the factory before Wonka could test anything more on him.
Cousin Itt has Scottish banshee ancestry.The Scottish banshee is a young woman whose red hair grows completely down to her feet, completely concealing her appearance. Change the colour to brown and you basically have Itt.
The Spy Twins from the 90's Addams Family cartoon are somehow connected to the spies from MAD Magazine's Spy vs. SpyBoth pairs look a bit similar. The only difference would be that they are not antagonistic to each other and they look slightly more humanoid.
Morticia descended from DraculaShe shares the same kind of lighting as the Bela Lugosi version, after all.
Tully Jr. wasn't in Values because...The Addamses ate him. Based solely on the exchange between Morticia and Margaret before the talent show in the first film.
The girl in Values talking about where babies come from is traumatized when Wednesday says "My parents had sex".She was then dragged out of the hospital screaming and crying.