How Growing Up In A Toxic/Abusive Household Can Mask Autistic Traits:
Tone: A common autistic trait is difficulty in recognising tone. But if you grew up in an abusive home, then learning how to distinguish different tones was often needed. This can vary from person to person. For me, I had to learn how to tell if my parents were angry at me or not, so I got very good at it, but anything else takes a while to figure out (once I realised that they weren't angry and therefore I wouldn't be hurt).
Sensory Overload: A lot of autistic people, including myself, suffers from sensory overload. Major triggers for me are sounds and bright lights. But I didn't even realise that it was happening before I knew I was autistic. Lots of kids from toxic homes tend to dissociate a lot, being completely withdrawn from the world to cope with trauma. This withdrawal can also dulls senses (your brain not registering sounds/lights/noises as much, making things feel very distant) and lessen sensory overloads.
Meltdowns: This also links in with the sensory overload. The dissociation might leave you completely feeling numb of emotions, which are the no.1 factors for meltdowns. Again, senses which can be triggers, are dulled because of this. If you grew up in an emotionally unhealthy environment, you may be punished for displaying 'unacceptable' emotions and meltdowns. This leads to withholding meltdowns and burnouts, which is extremely dangerous in the long run. Edit: you may also experience shutdowns instead and these are often unnoticeable or be mistaken for a dissociative/depressive episode.
Stimming: Stims may be punished by the people around you so obvious, healthy stims are often replaced with discreet ones. These may or may not be harmful, such as nail biting, chewing on your lips/cheeks, picking your skin, wiggling fingers, body tapping, etc.
Lying: Autistic people are somewhat known for having difficulty lying (because we often don't understand it/ feel that it isn't necessary, justice sensitivity may also come into this). However, many abused kids learn to lie early on to avoid punishment, be it physical, mental, emotional or societal. Being blunt and honest often doesn't work in an abusive household, since if the truth isn't 'acceptable' you get punished.
Special Interests: Abusers often use whatever is at their disposal to hurt you, be it your appearance or interests. If you grew up in an environment where your interests were mocked, then you may learn to hide it extremely well. My parents ridiculed my love for Harry Potter, which was and still is my special interest, to the point where I subconsciously buried my love for it and hid it to avoid getting emotionally hurt.
Social Cues: Lots of autistic people tend to be not very good at allistic social cues. For many, this manifests as being too loud in a conversation, interrupting others, being seen as self-centered because of how we show empathy, ect. However, for abused kids, lots of these behaviours are punished. You can't interrupt people or it would be a sign of 'disrespect', being too loud is an absolute no-no, you can't be seen as self-centered or you will get emotionally manipulated into feeling guilty. For me, I have to compensate by being seen as the quiet one. If I didn't know when to speak, I wouldn't. I tend to not talk above a certain volume. I scripted sympathetic responses in my head for scenarios.
Social Mimicking: Abused kids tend to mimic the behaviours of their peers to fit in. This can be joining in when their friends complain about how annoying parents are or having friendly banter without everything being seen as a threat. Maybe even hiding tears when going to school. This is done in an attempt to hide the fact that something is wrong at home, consciously or subconsciously. Autistic kids also mimic social behaviours in order to mask and fit in with social norms. So when you mask your autism, this can often be mistaken as you trying to hide symptoms of trauma and abuse.
Rejection Sensitive Dysphoria (RSD): This is something that I, and many neurodivergent people in general, suffer from. Rejections and criticisms, even constructive ones, feels like they're on me as a person (and not the piece of work I'm receiving feedback on). However, I didn't realise that it wasn't normal to feel like this. All. The. Effing. Time. Because whenever my parents criticised something, they made it very clear that it was about me personally. That test I failed? A sign that I was lazy and stupid. Forgetting to do something? There's something wrong with me and I would never be wanted if I keep on going like this. So it made it very difficult to tell when it was the rsd acting up or if it was truly an insult. Because I feel like this all of the time, it must be normal...right?
Tolerance To Change: Being resistant to change is a well-known autistic trait. However, when you live in an unpredictable environment, this trait often doesn't appear in major ways. I live in a very emotionally unstable home, meaning that my parents can be enjoying dinner and laughing one moment and hitting me the next. If rules change, no questions or objections allowed. Because of this, I appear to always be happy to go with the flow. Change of lunch location? Sure. Suddenly feeling everything go downhill and schedule disrupted? eh, at least it's not worse. But this trait appears in the small things for me. If a schedule changes, instead of having a meltdown, I would be stuck in executive dysfunction for a few days at most. Or I would be feeling very uncomfortable but I wouldn't have objections. If there's suddenly a new method to doing things, I will cling onto the old method for as long as I can. These are relatively small things that I could attribute to be 'quirky' or just stubborn. Not traits of autism.
These are from my personal experiences so there are probably many more. Feel free to reblog and add on anything else.