Guy to guy, ur son sounds like my 6 year old. He is the same way. Don't try to change him he will only rebell. Let him know u love him the way he is. If he isn't tough put him in Karate or something along those lines. Go to ur local library and ask about books to help u and ur son. Good luck.
Bringing up Boys by Dobson is good. I haven't read the book but have the video series based on the book and found it helpful.
Thanks to all who gave me their feedback. I have taken all your comments well and I shall start working on them. Are there any books for dads just as a reference point ?
Don't try to make him into a bold leader if he is not one, that will simply convince him that the person he is, is not OK in your eyes. This is a lot more damaging than losing a few fights.
If you want him to handle himself in fights (does he face that risk all the time)? just sign him up for a martial-arts course some time. Not with the message "this will toughen you up" but because he might find it fun.
Please don't equate who you are with who your son is. Every person is different with his own special gifts.
I forgot to address your mimicking question. There are some children who, when you talk to them you know immediately who they were spending time with that day - their actual speech changes to mimic the other's.
These children have the gift of great empathy and make good counselors, mediators, and teachers.
You're blessed with him.
The world is made up mostly of followers, or else the leaders wouldn't have groups to lead. ;D And I don't think you can change his basic personality from passive to aggressive.
What makes boys the most assertive, and the most comfortable, is love and respect from their dads and I don't fully feel like he's getting admiration from you. Boys who feel very admired by their dads do better in every area of life - and accept themselves.
Best thing you can do right now is stop trying to change him into someone he isn't, and enjoy and admire him for what he is - a cooperative, sweet child. Which I'd rather have than a sassy backtalker any day!
Tell him you're proud of him, you're glad to be his dad, you wouldn't change a thing about him, and he'll blossom.
Some people are just more peacemakers than others and it could just be his personality. Has he been evaluated by a developmental specialist? My husband and two boys all have autism spectrum disorder (ASD) issues. This COULD, but not necessarily, be related to an ASD, specifically Asperger's. That is what my husband and four year old have. If he hasn't been evaluated yet, I would get this done soon. If it is an ASD, it is better to know about it as early as possible. My husband didn't find out until he was in his thirties and he really wishes he had known he was an Aspie when he was younger so he could have done things differently that probably would have worked better for him.