I agree with the others that sometimes it's easy to forget exactly what you said, that it IS developmentally appropriate for 4yos to copy behaviors. I know that I sometimes have too high expectations for my dd because she's always seemed much older than she is.
The asynchronous thing hits hard when she's hyper-aware and extremely self-analytical about her behaviors after the fact. At 3 she could expound for 20 minutes on the potential causes of her bad behavior considering her mood, the poor influence of peers, the price of tea in China, you get the picture. LOL
The good news is I can assure you that now that she's nearly 8 she's much less likely to copy something dumb that another child does and can do that analysis BEFOREhand instead of after the fact.
We constantly emphasize 'control' with her. That she's in control of her own actions, reactions, body, thoughts, etc. She plays goalie for her soccer team so we relate the focus and control needed for the sport back to real life all the time. It's an ongoing, constant topic of conversation with her and at this point we probably sound like a broken record, but it's slowly working.
Possibly something like martial arts or yoga can help your dd develop more internally driven behavior than her being swayed by external forces. We have considered that, but the soccer goalie training is accomplishing that right now as it takes as much mental as physical effort.
good luck!
