Since we came back from Disney, we've been having a hard time with Alex. He's been much more aggressive than he was before we left. It was expected (although we always hope this time will be different) since he almost always has a spate of difficult behaviour after something enjoyable. For a walk, it might be an hour or so. For a weekend, the rest of the week. For a week away on vacation, often two to three weeks.
Our behaviour therapist pointed out that, from Alex's perspective, all the rules change during these activities. Since he lives in a world where things are constantly changing for no reason, he doesn't connect special activities to special rules. Instead, as he sees it, all the rules are up for renegotiation and aggression has always been a favoured tactic for him to renegotiate.
It's not a malicious thing. For him, aggression is a tool just like communication, except far more reliable. Without the empathy to understand that he is hurting others or the social understanding to realize how negatively this impacts his relationships, it must seem effective.
The therapist said we had to make sure we were absolutely 100% consistent to help him to understand that the old rules were still in place. Any change, no matter how small, would only reinforce the idea that everything was up for renegotiation.
It's difficult and exhausting but I'm doing my best to be 100% consistent.