Whats "Normal" for a 21 Month Old?

My dear friend's daughter was like this around that age, and she continues to be this way at just over age 3. She's playful and friendly when it's one on one with my son, but any more kids than that is what you describe (attached to mommy). This little girl is bright, happy, sweet, no developmental concerns... just seems to be her personality.

About being a "doormat":
One thing that came to mind is giving your son the words/tools to defend himself. Give him permission to say, "Help" or "I don't like that!" or whatever you feel is appropriate. Be honest with him about how other kids will but are not allowed to hurt him, take things from him without permission, etc. If he knows that you support what he is feeling and he has the right tools, perhaps he will address the conflict independently someday soon. At 18 months, my son didn't say much, but he sure was saying "Help!" when other kids would hurt him. At 3, he makes me proud with his maturity and ability to manage the conflict appropriately.

I agree with pp's. I also think that you should SHOW your son how to not be a doormat. Talk with the other moms that you playdate with. Explain that you are trying to teach your son how to stick up for himself and ensure they are ok with you getting involved...

The next time another kid steals his toy, get up, take your child's hand, walk over to the other child and say, "Johnny was playing with that. Would you please give it back." Then have your son say thank you.

Not only are you showing your son that you will help him, but more importantly HE needs to start doing it for himself. He's still young, but he'll get the idea not to just hand it over and need Mommy.

Imagine if someone came over to you (as an adult), took a magazine you were reading at the drs office and walked away. What would you do? I know it seems ridiculous, but seriously, think about it. It's not any better for an 18 mo old to take toys from another kid and think that's ok either. I understand they are young and learning, however I also think they need to start learning about how that makes other people feel.

Stick up for your son. Teach him now how to speak up for himself. Eventually he should do this on his own and not need your help. Just start encouraging him now to "use his words"...you'll be grateful that you started so early.

At this age role playing with him is good to teach him what to do. Show him how to find something else to play with or to speak up and tell the child it's still his turn. We did/do this with my son almost every day and he is good about things like this with other kids(but still will come to me sometimes and that's ok too he's still young!). Try sitting with the kids and engaging them along with your son so he sees you interacting correctly too. Kids still need us to play with them and teach/show them how to interact although they need independent time too! Good luck

I was painfully shy as a child too, I hate this trait but it's something I just had to overcome. I agree with the previous post. If another child takes his toy the other child he/she should give it back. You have to be there and show your son how to do things without hitting or giving in to the other kids.

It sounds to me that your child is just really sensitive and needs the reassurance from you when he's socially uncomfortable.

Our 3 year old is a follower. He's never the leader of the pack despite my husband and I both having strong personalities. We accept him as he is and hope he can be comfortable in his skin. Our daughter is very strong-willed but also very sensitive. She doesn't like to be told "NO".

If it were my child, I'd take him by the hand and show him something another child isn't playing with and re-engage him in the activities with the other kids.

Despite my strong personality, I'm shamefully shy in situations where I don't know people and wish I had more self-confidence to go introduce myself and interact with people I don't know.

But, I do think this is his normal. I'd be concerned as a parent if he didn't interact at all.
Good luck!